Comprehensive information about diving and undersea medicine for the non-medical diver, the non-diving physician and the specialist.
Asthma and Diving
Asthma - Divemaster?
Bad Air Problems
Bone and Joint
Actions With Possible DCS
Elbow Pain Caused by DCS?
Can DCS Cause Strokes?
Risk of DCS After Knee Surgery?
Recover from Paralysis?
Chronic Back Pain?
Outcome of DCS Joint Pain?
Return to Diving Post DCS
Missed Safety Stop = Near Miss?
DCS - Joint Aches Years Later?
Do I Have the Knee Bends?
Dehydration and Diving?
What Caused My Dry Mouth?
Suck It Up: SCUDA
What Makes Me Pee While Diving?
Deep Water Blackout
Why Did My Buddy Black Out?
Can I Dive After a Root Canal?
Diving with Dental Implants
Help! My Reg Makes Me Gag
Can Diving Cause Dental Problems?
Fire Coral Scars
Diabetes and Diving
Can I dive with diabetes?
How can diabetes affect a diver?
So who can and can't dive?
Guidelines for diving with diabetes?
Tell my dive instructor about my condition?
What is Diabetes?
Diving programs for Diabetics?
Warning Signs of Diabetes?
Drugs and Diving?
Dive Medicine Tips
Why Can't I Equalize One Ear?
Equalizing with Tiny Tubes
Blood in My Mask
What Is Causing My Sinus Problems Under Water?
What Caused My Nosebleed?
Frenzel equalization method
Can I Dive with a Cold?
Treatment for Middle Ear Barotrauma?
Diving and Tinnitus (Ear Ringing)
Can I Dive After An Ear Operation?
Can I Take Allegra and Dive Nitrox?
Prevent Ear Infections
What Do You Know About Star Otic?
Exercise and Diving
Exercise Affect My Diving Experience? Can I Dive After Running a Marathon?
Safe to Exercise After Diving?
Is Creatine Dangerous for Divers?
Contacts Damage My Eyes
Keratoconus and Diving?
Fear, Anxiety and Panic
Diving, Fear of Fish
Flying, Altitude after diving?
Altitude and Diving?
Flying After Diving: Rules
Diving after flying?
Free Dive After a Scuba Dive?
Diving on Hepatitis C Meds?
Help! Diving Gives Me Gas
My Ulcer Has Flared Up, Diving?
Dive After Donating Blood?
Can I Dive With Anemia?
Can I Dive With Leukemia?
Heart and Vascular Problems
Coronary Bypass Surgery?
Congenital Heart Condition?
Hypertension and diving?
Can I Dive With a Pacemaker?
Thrombosis in finger
Can I Dive with DVT?
Unnecessary Chamber Treatment Harmful?
What Can I Do About a Jellyfish Sting?
Stings and things
Fire Coral Burn: Long-Term Effects?
Should Older Divers Restrict Their Depths
Diving With a Chest Cold—Bad News
Causes of a Wet Cough After Diving?
History of Lung Collapses—Diving?
Risks of Diving in Shallow Water?
Non-Drowsy Seasickness Medication?
Land Sickness? Mal de debarguement? Sopite Syndrome?
I Throw Up Every Time I Dive!
Spinal Cord Injury, Diving?
Dive with a Spinal Cord Injury?
Return to Diving, Cartilage Repair
Return to diving, hysterectomy?
Can I Dive After a Vasectomy?
Do Teens Get DCS More Frequently?
Keeping Kids Warm in Cold Water
How Do I Keep Bugs From Bugging Me?
Women and Diving
Is It Safe to Dive While Pregnant?
Breast feeding and diving?
When it was suggested that the dive community reconsider its stance on asthma and diving at Divers Alert Network's 26th diving accident and hyperbaric medicine course in May 1995, a hot debate ensued. Asthmatics have bronchial airway obstruction, some more than others. If you remember your diving physics when you were certified, you know that Boyle's law is operative; as the depth and pressure change the volume of an air-filled space has to change (it gets smaller as you descend, larger as you ascend). While breathing compressed air, an asthmatic with obstructed airways can suffer pulmonary barotrauma or a burst lung on ascent. This can lead to arterial gas embolism with devastating brain and heart damage, possibly death (see: www.scuba-doc.com/asthma.htm).
The recommendations that you read on my web page come from the Undersea and Hyperbaric Medical Society's workshop on asthma. I believe that they are conservative and for safety's sake, should be used.
Larry Martin, M.D., offers the following advisory: "A history of bronchial asthma is disqualifying if there have been any attacks within two years, if medication is needed for control, or if bronchospasm has ever been associated with exertion or inhalation of cold air."
It's always a mistake to omit information from your certifying agency and your dive instructor. These rules and guidelines are placed there for your protection (and the agency's). It doesn't mean that they are fixed in cement and cannot be altered if it can be shown that you are not in any danger. It would seem that with 40 dives that you have pretty much found out that it was OK for you to dive safely (given no out-of-air situations). I recommend that you get your lungs checked out carefully before resumption of diving—mainly to rule out terminal airway disease. Possibly a spiral CT scan or a methacholine provocative test would be beneficial in determining any obstructive manifestations.
What does all of this mean to asthmatics who dive, or want to start? Hopefully, the changing perception of asthma and diving will encourage more asthmatics to seek appropriate medical clearance for diving from a doctor with experience in dive medicine. This should result in the screening out of those asthmatics who should not dive under any circumstances, while allowing proper instruction and education of the rest.
You shouldn't have any problems tackling divemaster-level training if you have reached the rescue level without asthma problems. However, there may be restrictions imposed by your certifying agency. Historically, asthma has been an absolute contraindication to diving. Diving physicians have felt that the risk for developing arterial gas embolisms is high and that asthmatics should not be permitted to dive.
However, the Undersea and Hyperbaric Medical Society decided that asthma should no longer be considered an absolute contraindication to diving. Rather, divers must be made aware of the risk factors. The following recommendations were made:
* Exercise- or
asthmatics should not
On the other hand, as in your case,
It would seem that some of the old safety concerns
and if your physician feels that you can dive, you
will probably get
just fine. Based on the latest medical data, the
YMCA protocols for
seem to be the most reasonable
It isn't wise to dive if you can't meet these
Depending upon what you mean by "bad" air, the answer is you probably won't get bacterial respiratory infections. Bad air is thought of as having been contaminated by hydrocarbons from a bad filter, or carbon monoxide from a faulty motor. Even "bad" air is pressurized and it is improbable that it would contain bacterial pathogens. It would be more likely that such an infection would be contracted from a focus of infection in your own upper respiratory passages—such as a nasal, sinus or throat infection.
This having been said, however, respiratory infections of various types can be contracted from poorly cleansed and decontaminated gear. Bacterial, fungal and possibly some viral infections can be transmitted from tubing, regulators and mouthpieces.
For more information, go to:
Can I Use My Asthma Inhalator Before I Dive?
use an asthma inhalator
before diving or not use it at all? I read that
Asthma sprays do not cause air
veins into the
arterial circulation. And, in fact, sprays
I need total
knee replacement. How will this affect my diving
able to return
to diving after complete rehabilitation from your
replacement would not
be affected by pressure, depth or gases since it is
For more information, go to www.scuba-doc.com/bone.htm
I recently strained my leg. I'm supposed to go diving in a couple of days. Should I go?
Leg strains vary in severity
associated with blood
clots. Some experts believe that there is
There are a couple of other factors to consider:
strain on a diver's legs. Getting back into the boat
might be a
What can you tell me about scoliosis and how it may affect diving?
Probably the main concern with
scoliosis is the possibility
of decreased pulmonary function.
Another concern would be
spine from lifting
heavy weights and tanks. Proper gear
You will likely have more
gearing up, entries
and exits, but this difficulty disappears in the
broke his elbow in a skiing accident. He had
He is now
interested in pursuing
a career in commercial diving and has been asked to
Whether the site of a fracture
point for bubble
formation because of changes in blood flow
The agency may be requiring an
baseline for comparison
later, should the need arise.
If his fracture has completely
his doctor and he has rehabilitated his elbow
If you suspect any type of decompression illness, start breathing 100 percent oxygen as soon as possible. Oxygen kits are standard equipment on every reputable dive boat in operation today. Pure oxygen is first aid for any suspected decompression illness because it increases the rate of nitrogen elimination and decreases the size of offending nitrogen bubbles—buying you precious time until you can get medical help.
If you're not sure you have DCS, call DAN's nonemergency number (919-684-2948) to get expert assistance in deciphering your symptoms. DAN has doctors on call 24 hours a day who can help answer questions, as well as ask a few of their own, and arrive at some sort of decision about your complaints.
Did Decompression Sickness Cause My Exhaustion?
On a recent dive trip, I made a dive to 40 feet for 30 minutes, and went to the same depth for the same amount of time on my second dive later that day. The next day I went snorkeling and made a free dive to 20 or 25 feet and forgot to exhale on my way up. I have been feeling tired lately—not extremely tired, but more than normal for me. I also have ringing in my ears, though I always have that. None of my joints ache. Am I overly worried? Could I just be worn out?
Fatigue should be considered when evaluating diving accidents. It is a symptom of decompression illness and often is the only complaint a diver has. Usually, when a diver receives recompression treatment for limb pain, the underlying fatigue disappears along with the pain.
Exhaustion is also a prominent symptom of many other illnesses. Given the dive profile that you describe, your fatigue is most likely not due to decompression sickness. If you continue to have problems, request an exam by a chamber physician and obtain treatment in a chamber. The fatigue might respond to the treatment.
Was My Son's Elbow Pain Caused by DCS?
Shortly after surfacing from an 86-foot dive, my 12-year-old son complained of moderate to severe pain in his elbow. Our computers were one dot in the yellow and our ascents and safety stops were by the book. I experienced no DCS symptoms. After the required surface interval, we made a second dive to 56 feet, even though my son's elbow still hurt.
When we returned to the boat, my son's elbow pain had stopped and didn't return. Is it possible he was slightly bent on his first dive, and that he "decompressed" on the second dive? Also, is there anything about a growing child's physiology that would predispose him to DCS?
It is entirely possible that your child had bubbles in his elbow, particularly if there was no trauma or previous history of arthritis. Joint pain from DCS would improve with recompression but would most likely have returned and worsened after the ascent from the second dive. This is not something you can prove, although an MRI of the elbow might be good to have in case of further difficulty.
There are issues to consider with children diving, such as diving's potential effects on lung, bone and other developing tissue. Children divers should stick to dive profiles that minimize their DCS risk to eliminate possible injury to growing tissues, such as the growth plates of bones. There are no studies that indicate that these growth plates (epiphyseal plates) are a particular problem—just suspicion that an area of increased vascularity might be more susceptible to bubbles. Since the damage that can be done to bone is directly proportional to the length of time at depth, time and depth should be restricted in the growing teenager. A teenager's ascent rates and safety stops should be carefully monitored.
Also of concern is patent foramen ovale, which can allow venous bubbles in the right side of the circulation to cross over into the arterial side and cause clinical bends or arterial gas embolism. It is known that the rate of closure of a patent foramen ovale in the heart is highly variable and in some children, it will not have closed by age 7. This is something that your pediatrician can check.
Can DCS Cause Strokes?
A friend of mine suffered some strokes a couple of years after one doctor said she might have decompression sickness. At that time, she was an airline attendant and flew after a dive, supposedly with enough time in between the dive and flying to be safe. A few days after the flight, she experienced some symptoms of DCS. Her physician said she might have DCS, but that it was too late for recompression therapy. She has since had the strokes and had many tests. Some doctors say she has a connective tissue disorder, and others say it is because she got bent, and that she could die suddenly. The tests did find damage to her brain. If she had DCS, could it have caused the air bubbles to constrict blood vessels in the brain, leading to her strokes?
It's improbable that your friend's strokes are related to decompression sickness. The possible relationship to a patent foramen ovale—a condition where blood can flow from the right chamber to the left across the heart without passing through the natural filter of the lungs—might be the reason, but in this case it's impossible to prove. In a diver with a PFO, the bubbles could bypass the lungs and flow directly to the brain, where they could cause what are essentially mini-strokes. Over time, enough of these small strokes could cause neurological or cognitive deficits. If your friend has not been evaluated for an abnormal right-to-left shunt in the heart, then she should consider this. For more information on PFO, go to www.scuba-doc.com/pfo.htm.
Bubbles from a decompression accident don't linger, but are absorbed gradually. Recompression of the bubbles is done because this improves the outcome markedly—even as much as several days later. However, the damage that these bubbles cause with subsequent scarring can lead to residual neurological changes, varying with the part of the brain left scarred. It's impossible to say whether your friend's previous decompression accident or the strokes have caused her difficulties.
There is no evidence that surgery, fractures or other injury increases the incidence of decompression in an area. Risks of DCS are often predicated on unproven assumptions of bubble accumulation at sites of altered blood flow, either increased or decreased.
You will likely have more difficulty than usual with gearing up and doing sea entries and exits, but this disappears after you are in the relatively gravity-free environment of the sea.
If your surgeries have completely healed to the satisfaction of your surgeon—then you should be able to dive without difficulty.
Can a Person Recover from Paralysis Caused by DCS?
A friend of mine got decompression sickness. One week after getting bent, after having three recompression sessions, six hours each, he still has no use of his legs. He is paralyzed from the sternum down. Is there any way he will be able to walk again?
A friend of mine got the bends while diving. He is now in a wheelchair. Is this reversible?
The answer in both cases is most likely no. The bends is what divers call decompression sickness. In its worst form it can cause permanent neurological damage to the spinal cord and brain. In the U.S. alone, Divers Alert Network (DAN) reported 590 cases in 1995. Of course, there are many millions of dives made each year by the estimated millions of divers in the U.S.
The condition is prevented by carefully following the rules of diving at all times and is treated by early recompression in a hyperbaric chamber. Treatment is generally continued until there is diminishing or no response to the treatment. Response is highly variable and not readily predictable. Oxygen administration after recompression treatment is helpful in reducing recurrences of DCS. Rehabilitation programs often enable paralyzed patients to return to some level of function. The attending physician should be able to tell you more about your friends' outcomes.
In the last few years, my back has been "going out," landing me in bed for about two days. The last two episodes occurred on a dive boat, just after a dive. Both times, I felt a "pop" in my lower back. I am 39 and in good health. I work out three to five days a week, riding a stationary bike and lifting weights.
An orthopedic specialist says I have some arthritis in my right hip joint. He is concerned that the chronic pain is because of a diving-related injury. He said I might have a form of bends, and each subsequent dive is aggravating the injury further. I have an MRI scheduled in a month to see if bubbles are concentrated in my lower back area. What do you think?
I think this is a mechanical back
diving. You need
to be sure that the arthritis of the right hip is
A thorough examination by a neurologist could settle
this once and for
Bubbles wouldn't show up in diagnostic testing as they don't hang around very long and are absorbed by the body. Their "footprints" remain as scars from the resulting tissue damage and as inflammation, which occurs with a decompression accident. Subsequent diving does seem to concentrate new bubbles in or around the areas of previous damage. The MRI might show damaged areas, but you would surely have had some neurological indication of this.
Outcome of DCS Joint Pain
Will the joint pain resulting from untreated decompression sickness disappear after time or will it just get worse?
Joint pain that is due to a decompression accident is caused by several things:
the pressure caused by the actual presence of bubbles in the tissues around the joint
the production of chemicals called kinins that cause an inflammatory response similar to arthritis
damaged when clotting
and other protective systems are triggered,
resulting in pain,
Compression, such as a blood
cuff or a
Ace bandage, usually causes an
Bubbles have been found in
what was thought
to have been successful treatment of
Not entirely. There are many different forms of decompression illness. Some leave few indications of its presence; but some leave significant scarring, particularly in the central nervous system.
Many physicians believe a person should not return to diving if he or she has experienced severe neurological spinal or cerebral decompression illness (Type II) with residual neurological symptoms. One of the reasons for this is the known increased risk of recurrent decompression illness in the area of scarring from the previous sites of the bubbles.
The recommendations for diving after a bout with the bends:
# Type I DCS—If uncomplicated and produced by exceeding dive profiles or ascent rates, a diver may return to diving in four weeks.
# Type I DCS, unexpected—Should return to diving only after ruling out diseases and factors that might increase susceptibility. Change of diving to a more conservative pattern.
# Complicated Type I; neurological and other Type II DCS—Return to diving in a limited manner (no decompression dives, bottom times halved, maximum depth 50 feet and surface intervals of six hours) one month after identifying all causes and undergoing full neuropsychological assessment.
The sixth Caribbean dive of our
easily, but when
I ran low on air, my fiancée and I
I don't think so. Coming up
typical after a
dive. Even though her ascent might have been
Can DCS Cause Joint Aches Years Later?
My 50-year-old husband suffered a hit of decompression sickness 17 years ago. He was in a recompression chamber for at least eight hours. At the time, he only dived about once or twice a year. He has not dived since then. In the last few years, he has had a lot of joint aches. His physician told him the joint pain could be from the decompression accident. Can a person experience pain this long after a dive accident?
If your husband has a condition called aseptic necrosis of the bone, which causes a collapse of the joint surface and results in joint pain, his diving accident could have caused it, even many years after the injury. This condition is relatively easy to diagnose once X-rays have been taken. When the surface of the joint (generally the shoulders, hips and knees) is affected by the necrosis, physicians usually recommend joint replacement.
After a Caribbean dive trip, a
the back of my knee. We made 17 dives in
First, we would agree with DAN
DCS; nor is there
the possibility of gas being trapped in the
The most likely cause of the
rupture of a small
superficial vein in the back of the knee
I don't think this is a
Your doctor might
want to run a few studies on your
After two days of diving recently, I developed an irritated throat that progressed to a rather nasty condition—dry and quite sore—for another six days after returning home. Because I am scheduled to take a weeklong live-aboard trip soon, I need some advice on how to prevent dry mouth and throat irritation from repeated diving.
- via email Allen, Texas
It may be that your problem was a viral pharyngitis or some other infectious condition. It also could have been caused by not swallowing while under water. Saliva can help prevent the dry mouth caused by the dry air in your scuba cylinder. Your saliva glands can be stimulated by using the SeaCure mouthpiece (www.seacure1.com) or placing minty toothpaste on your mouthpiece.
If your dry mouth was caused by dehydration, however, you need to examine your habits before you dive to prevent dehydration on your next dive. The air in your scuba tank is as dry as the Sahara, the moisture having been removed from it in order to protect the inside of your tank and regulator from corrosion. Each incoming breath of dry air picks up moisture from your throat and lungs and carries it out when you exhale, so every breath represents a loss of water.
How much? Not as much as you'd guess
cotton-mouth feeling that
results. On a four-tank day you'll breathe about 260
cubic feet of dry
air (assuming 80-cubic-foot tanks—actually 77.4—and
a minimum pressure
of 500 psi). The maximum amount of water that much
air could have
(at 100 percent humidity, 86F) is about one cup. In
fact, you probably
lose less. Research reported in the journal
that most of this water loss occurs in the first 15
minutes when your
respiratory tract dries out. Regulators that trap
moisture in the
stage to moisten incoming air lessen, but probably
the drying effect of breathing tank air.
Yes, a cup of coffee is mostly water. But the caffeine is a diuretic, sucking water out of your tissues and sending it to your bladder. As a result, drinking 12 ounces of coffee results in 12, 15, 20 or more ounces of urine and a net loss in your hydration score.
Caffeine is sneaky. It's in more foods
than you might
think. Popular soft drinks have a range of caffeine
36 and 48 milligrams, with Jolt Cola the chart
topper at 72. Coffee has
the highest concentration, up to 180 milligrams per
five-ounce cup. Tea
can have as much as 50 milligrams per cup, and both
tea and chocolate
loaded with substances called xanthines, which are
Divers with a severe dry mouth problem may want to consider another equipment solution, the SCUDA (self-contained underwater drinking apparatus) made by SCUDA Marketing. The SCUDA is a wine-skin type device that holds water and allows you to drink through your regulator—squeeze the bag and water squirts into your mouth. The SCUDA doesn't affect the breathing characteristics of a regulator, but because it attaches to the primary hose, it does affect regulator ergonomics. There's also the possibility that you'll gag on water squirted inadvertently or too forcefully into your mouth. The SCUDA is not a great idea for most divers, but those with serious dryness of the mouth may want to try it.
When diving, I suddenly get the
even though I voided
only minutes before. Why do I need
This physiological phenomenon
a fancy term for your body's response to
like caffeine before
This is probably "deep water blackout" given a normally functioning regulator. This condition has been described by "Diving Medicine Online" consultant Dr. David Elliott as a combination of low partial pressure of oxygen, high partial pressure of nitrogen and high partial pressure of carbon dioxide. Your buddy's improvement on ascent is revealing. Your quick action probably saved your friend from arterial gas embolism and possible death. I'm delighted to hear that you had oxygen on board, as this was the treatment of choice. Any possible benefit from recompression is a moot point now, of course.
The second stage of his regulator
malfunctioned and this
might have started the whole landslide of hypoxia
and hypercarbia and
depth caused the high nitrogen. I have seen one
similar case in an
diver at 90 feet, which resulted in the rescue and
embolism due to a "lack of air at depth" and near
drowning. His buddy
not as attentive as you, however, and pulmonary
barotrauma occurred. He
had plenty of air in his tank on surfacing.
I heard a strange rumor that
for two weeks
after getting a root canal—that on
Your concern is not a rumor. If
left in the
end of the root canal, this air could implode on
If you are about to have a root canal or if you've just had one, follow these recommendations:
filled to the
top to avoid accumulation of compressed gases and
The only concern about diving with dental implants would be whether you can clamp down on the regulator's mouthpiece without difficulty and without damaging the implants. If the procedure your dentist performed has been successful, and the implants can withstand normal biting pressure, you should be able to dive again. Your dentist can make this determination after he or she has given you the OK to resume normal eating and chewing.
You could try mirror biofeedback. Using a mirror, start with a snorkel, inhale to the count of 4 and exhale to the count of 6 (relax as you exhale). Watch your face relax in the mirror. If you see your face, jaw, eyes, neck and shoulders relax, then you are doing it right. Then try the same exercise with tongue depressors in your mouth. Finally, try it with your reg mouthpiece.
It may be that the mouthpiece of your reg needs to be trimmed. Remove any excess silicone that extends back to your back teeth and trim the excess that hits the roof of your mouth. Another option is to swim laps in the pool with a snorkel until the gag reflex goes away. If you only experience it with a regulator mouthpiece and not with a snorkel (having a virtually identical mouthpiece), it may be that the gagging is anxiety-related, and not anatomical or physiological in nature.
Some dentists sprinkle sugar or salt on the tongue or palate before making dental impressions to inhibit the gag reflex. A topical anesthetic works well—especially Dyclone, which is longer-acting.
Finally, if these suggestions don't
consider getting a
full face mask.
first time this
past winter (seven dives in two-and-a-half days) and
Your problem could definitely
diving. First, you
may have already had dental work that was
Second, you could be using a
causing the repair work to loosen. By
For more information: www.scuba-doc.com/dentprbs.html.
I came into contact with what I
coral in the
British Virgin Islands about five weeks ago.
Coral scrapes do have a
and infected. Occasionally, coral
Initially, wounds should be
vinegar or whatever sterile fluid you have
If the wound does not appear to
24 to 36 hours,
check with your doctor to see if you
Cormax is the trade name for
topical steroid cream.
It reduces or inhibits the actions of
What is seabather's eruption,
worry about it?
The skin condition known as
eruption, also called
swimmer's itch, appears as a rash of raised
Seabather's eruption can be
produce larvae with nematocysts, including
Outbreaks of seabather's
March and August in the Caribbean and
In other tropical waters,
appears to be
associated with periodic anemone larvae
Answer: The short answer is—maybe.
Until the middle of the 1990s, the official medical advice was that diving with diabetes was too risky. Thanks to research by Steve Prosterman of the University of the Virgin Islands, the Undersea and Hyperbaric Medical Society, the Divers Alert Network (DAN) and the British Sub-Aqua Club (BSAC), we've learned a lot in the last few years, and today, it's a case-by-case decision based on how well the diabetic controls his condition.
If you're a diabetic who dives or wants to dive, the first step is to consult your personal physician to learn as much about controlling your condition as possible.
Answer: Diabetics can be at risk from the effects of both the condition and the methods of controlling it.
* The possibility
loss of consciousness
from hypoglycemia has been the big obstacle to
Answer: Any diabetic who can't recognize hypoglycemia (low blood sugar), hyperglycemia (high blood sugar), or who is diagnosed with ketoacidosis (acidic condition from breakdown of ketones) or organ disease (kidneys, eyes, heart) must be disqualified. Sorry, the risks are still too great.
The good news: Diabetics who practice excellent self-management, understand the relationship between exercise and diabetes, and are disciplined enough to follow these guidelines are qualified for conservative sport diving without problem.
* Wear a medical ID
and also a diver.
"The important thing is to find the direction of the blood glucose. Under no circumstances should a dive be performed if the blood glucose is dropping," Prosterman says. "If it's going down, take carbos to stabilize it. Usually it can be corrected after the second test."
If blood glucose levels are rising, aim for a minimum reading of 120 to 130mg/dl before diving.
* Pack a dive kit. This must include: two separate packs of oral glucose paste or tablets in waterproof containers; an emergency intra-muscular injection of glucagon to rapidly raise dangerously low blood sugar levels (make sure someone in your dive party is capable of administering the injection); and a glucose-measuring kit with instructions.
During the Dive
* Always carry oral
water. A glucose
gel in a plastic container, like InstaGlucose, is
recommended. Both the
diver and his non-diabetic buddy should carry two
After the Dive
* Check your
By tracking the drop in blood sugar after dives,
diabetics can learn to
better control their condition.
For years, diabetic divers have hidden their conditions in order to participate. As the dive community begins to recognize the new rules for diabetes, the safest—and most responsible—course of action is full disclosure. It's important that your buddy and divemaster be fully aware of potential reactions and how to respond to them.
There are two main types of diabetes. Type I, also called insulin dependent diabetes, normally affects children or adolescents.
Type II, also called non-insulin dependent diabetes or adult-onset diabetes, accounts for 90 percent of cases and usually occurs in overweight adults.
Treatments for diabetes include daily insulin injections to lower high blood sugar levels, oral medications, regulating the diet, exercise and constant blood glucose monitoring.
There's no better role model for diabetic divers than Stephen Prosterman, diving supervisor at the University of the Virgin Islands. Diagnosed at the age of nine, Prosterman never let his condition get in the way of an active lifestyle. And when he moved to the islands more than 20 years ago, that lifestyle soon included diving.
His love for the sport led him to create the first protocol for responsible diving with diabetes, and this work spurred much of today's ongoing research. It also led to Camp DAVI, an annual summer program for diabetics 17 and older that uses diving and other adventure sports to teach campers how to tightly manage their condition. The program, overseen by Dr. Doren Frederickson of the Kansas University School of Medicine, also advances research into diving with diabetes.
* Any family
According to the National Diabetes Information Clearinghouse, 798,000 new cases of diabetes are discovered each year. Unfortunately, an estimated 5.4 million people remain undiagnosed and are at risk for the long-term damage that can result—including heart disease, stroke, high blood pressure, blindness, kidney disease and nervous system damage.
* Go to the
section of "Diving
Medicine Online" at www.scuba-doc.com and look up
or disease for which the medication is being given
and find whether
are any prohibitions against diving with that
condition or while taking
It is my understanding that Benadryl (diphenhydramine) is considered to be a sedating antihistamine, and is, in fact, sometimes used as a sleep aid. I also recall seeing a caution on a Benadryl box indicating that it "causes marked drowsiness." If this is correct, would Benadryl be contraindicated for divers? You recommend it for divers not once, but twice in the Oct. '99 issue.
Benadryl is an over-the-counter medication that causes some side effects in some people. The fact that it causes drowsiness in some people does not indicate that it would necessarily be dangerous to all divers. Diving per se is not known to increase its effect. It is doubtful that the FDA would turn it loose if there was major danger. After all, there are a lot more drivers than divers.
Every drug or medication has some side effects on some people. One should not dive after taking this or any drug until their response to the drug has been determined.
However, since the mild depressant effects of antihistamines are additive to those of other drugs affecting the central nervous system, patients should be cautioned against drinking alcoholic beverages or taking hypnotics, sedatives, psychotherapeutic agents or other drugs with central nervous system depressant effects during antihistamine therapy.
Diphenhydramine should be used with caution in patients with a history of bronchial asthma, increased intraocular pressure, hyperthyroidism, cardiovascular disease or hypertension, all of which are clear hazards to divers if uncontrolled. Other listed adverse effects of Benadryl include: drowsiness, dizziness, dryness of mouth, nausea and nervousness. Other infrequently reported effects are vertigo, palpitation, blurring of vision, headache, restlessness, insomnia and thickening of bronchial secretions. Allergic reactions, diarrhea, vomiting and excitation may also occur.
- via email, New York, N.Y.
It is possible that you have some type of blockage of your nasal lining near the opening of your eustachian tubes, possibly polyps, bony growths, nasal septal deviation or allergic rhinitis. If it comes and goes, the most likely cause would be that the mucosa is swelling at various intervals, possibly as the result of allergy, irritations from fumes or from congestion from any of a thousand other sources. This may have caused some middle ear barotrauma, with swelling and serum accumulation in your middle ear.
If a good ear, nose and throat exam fails to expose any pathology in the back of your nose, then you might need to check into your diving technique. Descending feet-first on the anchor line or a down line can help you rise slowly just a foot or two to take the pressure off and help you clear easily.
Try a Different Clearing Technique
You might also want to try using a different technique for clearing your ears. The Valsalva maneuver--pinching your nostrils and blowing through your nose--is the most commonly used technique, but might not be the best one for you. One problem with the Valsalva maneuver is that it doesn't activate muscles that open the eustachian tubes, so it may not work if the tubes are already locked by a pressure differential (see illustrations). It's also easy to blow hard enough to damage something. Instead of using the Valsalva next time, try one of these:
* The Toynbee
or blocked against your mask skirt, swallow.
Swallowing pulls open your
eustachian tubes while the movement of your tongue,
with your nose
compresses air against them.
In addition, you can use medications that help reduce the swelling around the opening to the eustachian tubes. Most people use and get good results from oral Sudafed tablets. Afrin nasal spray, for a day or two only, also is helpful, but can cause troublesome rebound congestion. Taking oral Sudafed throughout a dive trip would not be harmful, nor would it cause rebound congestion. The newer antihistamines (Allegra, Claritin and Zyrtec) might be helpful, taken on the advice of your physician. Flonase is also helpful for some people.
For more information on dealing with ear troubles, go to: www.scubadiving.com/training/medicine/earproblems.shtml or www.scuba-doc.com/entprobs.html.
Why Can't I Equalize One Ear?
My right ear equalizes perfectly, with no problems at all, but my left ear is another story. Everything I've tried—from using an anchor line to slow down my descent to clearing my ears before the dive—has not helped. Is there anything that could be causing this problem?
Unequal clearing usually indicates one of two things: poor technique or some abnormality in the back of the nose causing blockage of the opening to the eustachian tube.
Though you've tried various methods to help clear your ears, read "Pain-Free Equalizing," in case there is a method you haven't tried.
If it's an abnormality that's preventing you from equalizing, there is good news. Lots of these can be corrected easily, including polyps, allergic rhinitis and bony growths around the opening to the eustachian tube. A visit to an ear, nose and throat specialist can determine if you have one of these conditions.
There are no scuba apparatuses or equipment that will perform the function that you wish. There probably are people who are born with congenitally small or narrow Eustachian tubes, but this would definitely be the minority. Most people have a correctable cause for their inability to equalize when diving. You are strongly advised to see a good ear, nose and throat specialist who is diving oriented and find out if you have some problem that can be altered surgically.
I'm assuming it's a mixture of blood and mucus. Am I going to live? Will I ever play the piano again?
The old "blood in the mask" gambit is guaranteed to scare the diver, get attention from his buddy, attract sharks and other top-of-the-food-chain animals, and turn off the ladies (and anyone else who doesn't like orangish-pink snot). You'll survive, though I don't know if you'll ever play the piano again.
All kidding aside, yours is a frequently asked question (because it happens frequently) and the simple answer is that it is harmless, usually caused by mask squeeze, sinus barotrauma or excessive nose-squeezing with clearing attempts. If you are concerned, it might be wise to go to an ear, nose and throat doctor and be certain that you don't have something that can be corrected—such as septal deviation, chronic rhinitis, polyps or tumors.
For more information, go to:
an ongoing sinus
infection that is only evident when I dive. I take
You probably have something
outlet of the affected
sinus—such as a deviated septum,
This is apparently not a
causes blockage due to pressure changes on
The appropriate antibiotic
the type and
kind of bacteria present—as determined by
This problem will continue until you find the cause and get it managed properly, possibly surgically.
Q: I have
certified for one
year and have completed approximately 30 dives. I
was recently diving
group for the drift
dive and sometime later realized there was warmth
around my nose and
Do you have any idea what caused the pain? Should I have aborted the dive? Should I have done the second dive?
associated with diving are almost always due to
aborted the dive
if you bled enough to be unable to see through your
persistent and heavy,
then you should seek medical consultation from a
You'll want to refer to "The Diver's Complete Guide to the Ear" in which we describe all the methods for equalizing your ears. The Frenzel maneuver described by DAN is: "Adding air to the middle ear by closing the nose, mouth and glottis voluntarily, then driving the tongue backward, which acts as a piston to compress air into the nasal cavities and through the eustachian tubes." In other words: Close your nostrils and the back of your throat, and thrust your tongue against the soft palate. This gently forces air through the eustachian tubes.
Can I Dive with a Cold?
I canceled a recent dive trip because I had a bad cold. Was that really necessary?
You probably did the right thing. Nasal congestion and blockage can lead to sinus and middle ear barotrauma. And the resulting sinus infections and middle ear damage and infections can cause hearing loss and balance problems.
Is there a specific treatment for middle ear barotrauma to help eliminate the pressure and fluid in the ear? How long does this generally last?
Barotrauma of the middle ear occurs from swelling and bleeding after the ear is damaged from a diver's inability to equalize pressures on descent or ascent. Treatment involves reducing the swelling, draining the serum and blood through the eustachian tubes, and treating any infection that occurs when the eustachian tubes are blocked.
This treatment generally consists of oral decongestants and antibiotics. Antibiotics are used only when there is fluid in the middle ear and there is the possibility of infection. If perforation is present, oral antibiotics should be used. Ear drops are not advised if there is perforation of the eardrum.
Middle ear barotrauma usually clears up anywhere from several days to six weeks, depending upon the degree of damage done and whether or not there is a perforation of the eardrum.
Divers with middle ear barotrauma should not dive until all symptoms have cleared. If there has been perforation, do not dive for at least six weeks after the perforation has healed. No ear drops should be used in the event of rupture, as damage can be done to the middle ear.
Ringing in the ears or "tinnitus" is one of the most prevalent and bothersome of symptoms related to diving. Tinnitus may be caused by damage or disease anywhere along the path of the auditory system. In divers, it can be related to TM joint pressure from clamping down on the mouthpiece, wax buildup in the ear canal with tympanic membrane irritation, barotrauma to the middle and inner ear, decompression illness involving the inner ear or rupture of the round window with perilymph fistula. It is most often found in association with vertigo (dizziness) and there is usually some deafness.
During the last two decades, hyperbaric oxygenation therapy (HBO) has been used in the treatment of sudden deafness and chronic distressing tinnitus, with mixed results. It should be emphasized that this and other newer methods of treatment are still under evaluation. At this time there is no universal, symptomatic or specific treatment for tinnitus.
What divers can do:
* Get a good
nose and throat doctor. The tinnitus may not be from
diving at all. If
it is related to diving, early treatment may be
Additional information can be obtained from the American Tinnitus Association (P.O. Box 5, Portland, OR 97207-0005).
On the web, go to:
Can I Dive After An Ear Operation?
I am 37 years old and have been diving for 12 years. I have completed just over 500 dives. Recently, I developed a ringing in my ears that specialists call otosclerosis. This ringing is not related to my diving. Instead, it appears to be a calcium buildup on one of my inner ear bones that is pushing the inner bones against my eardrum. This contact causes constant ringing.
The ear specialist said I could have an operation in which the problem bone and the calcium would be removed and replaced with a plastic bone. Most or all of the ringing would go away, but I'd never be able to dive again since the operation would involve cutting through my eardrum. The risk for further problems once you cut through the eardrum is too great, therefore I'd have to quit diving.
Is this true?
Otosclerosis is the abnormal growth of bone of the inner ear. This bone prevents structures within the ear from working properly and causes hearing loss and ringing. Otosclerosis usually affects the last bone in the chain, the stapes, which rests in the entrance to the inner ear (the oval window). The abnormal bone fixates the stapes in the oval window and interferes with sound waves passing to the inner ear.
In an operation called a stapedectomy, a surgeon (otolaryngologist or otologist) bypasses the diseased bone with a prosthetic device that allows sound waves to be passed to the inner ear. The problem for divers is that the pressure changes from clearing the middle ear can force the prosthesis through the oval window due to the lack of normal muscular support. This could result in permanent damage to the inner ear.
Unfortunately, I agree with the advice you received from your ear specialist. The risk of injury from pressure changes would be quite high and could end in permanent deafness or severe inner ear damage.
Allegra has none of the effects that mimic adrenaline and is safe to use with nitrox. It reduces the risk of oxygen toxicity, unlike some other allergy medications that may actually increase the risk of oxygen toxicity. Another point: Allegra has fewer sedative side effects than other allergy medications.
Not all ear infections are the same, nor is all water that you dive in the same. I assume that your query concerns otitis externa, or infection of the ear canal. It may be that you haven't gotten rid of the first infection before you dived again. Sometimes these infections require a full 10 days of treatment with ear drops containing an antibiotic.
Ear canal infections can be easily prevented by the judicious use of ear drops after each dive. These drops are for changing the acidity and moisture of the ear canal so that organisms cannot survive. Cleanse external canals of occluding wax and avoid trauma from Q-tips, bobby pins, etc. Use a good ear solution to maintain a slightly acidic environment. SwimEar or Star Otic.
What Do You Know About Star Otic?
I read that Otic Domeboro is the best product for preventing swimmer's ear, but it's expensive and available by prescription only. Solutions containing alcohol are readily available, but irritate my ear. A "home brew" mixture is a possible alternative, but I don't think this a prudent alternative. I did some research and found a product called Star Otic. It is a Modified Burow's Solution (essentially Otic Domeboro) and is available over the counter for about $5. I tried it on a dive trip a few weeks ago, and it worked great. Is it OK to use?
Star Otic is an alcohol-free solution and contains Modified Burow's Solution, a mixture of aluminum acetate, acetic acid and boric acid in a propylene glycol vehicle. Cost is significantly less—$3.79 per 5-ounce bottle—and it's safe to use.
Incidentally, a homemade solution of half vinegar, half peroxide is safe and effective. For more information on ear drops, go to www.scuba-doc.com/otext.htm.
I am an extremely fit 62-year-old who regularly works out at my local gym. I am planning a trip to Grand Bahama Island and would like to continue my regular gym routines coupled with extensive scuba and skin diving. How much is too much? I have 40 years of diving experience, but this is the first time I will have the chance to experience virtually unlimited diving in warm water. What would you suggest?
First, congratulations on keeping yourself fit. This is something that you can continue to do on your dive trips, with certain precautions. The results of some studies suggest that the risk of neurologic decompression illness is reduced by physical conditioning, and the effect is independent of differences in age and weight.
You definitely should not exercise in the time period immediately after a dive while off-gassing or within several hours after a series of dives. Also, scotch any plan for mountain climbing immediately after diving.
If you exercise and plan to dive
exercise, it would be
wise to allow for a cool-down and rehydration
Even if the race includes ascending to significant altitude, as might be the case on Maui, you can dive. Make sure you're completely rehydrated from your race, as dehydration is a real risk for decompression accidents. It is also recommended that you have a cool-down period of several hours between your dives and any strenuous activity.
You should not, however, run or hike to altitude soon after diving. Stay at sea level at least 12 hours after a single dive or 24 hours after multiday, repetitive diving.
We get asked this question a lot, especially from dedicated runners, swimmers, hikers and gym rats. It takes about 24 hours to eliminate residual nitrogen from your body. There is some debate about whether exercise, especially strenuous activities such as running or mountain climbing, is risky during that period of time. Those who advise divers not to exercise immediately after diving say that it might increase the chances of bubble formation from residual nitrogen levels.
The research on exercise after diving can be contradictory. There are some inconclusive reports that point to physical stress as the cause of DCS in some divers who exercise after diving. But there is also evidence that exercising while decompressing is helpful in reducing decompression accidents.
Q. I have started a
use of creatine monohydrate as a
will not affect
your likelihood of developing decompression
I'm afraid your dive instructor is wrong. The only real risk you run by wearing contact lenses under your mask is financial: If your mask floods, your tiny, transparent investments can be washed out of your eyes and into the great blue. Whether you decide to use prescription lenses or contacts is a personal preference. If your eyes are stable and your vision is not changing, the prescription lenses may be your best bet in the long run, though a corrective mask is useless before you put it on and after you take it off. With contact lenses, you never lose visual acuity, even on the boat. For more information, go to www.scuba-doc.com/diveye.htm.
Quick Tip: Diving with Contact Lenses
* Wear soft
Will My Son's Eye Condition Prevent Him From Diving?
Our son was just diagnosed with an eye condition called keratoconus, a thinning of the corneal lens. According to the handouts given to us by his doctor, he can do sports activities as long as he wears protective eyewear. We're concerned about the pressure changes associated with diving. He is 13 years old and is about halfway through diving certification. That's on hold until we know more about the condition and how it relates to diving.
Your son can dive, depending on his visual acuity. Keratoconus is not affected by pressure and depth changes. The possibility of a mask squeeze is a concern and might be a hazard.
Keratoconus can be corrected with a rigid gas-permeable contact lens (or surgery). Unlike hard lenses, gas-permeable lenses—whether they're extended-wear or disposable—won't allow bubbles to get trapped between the lens and your eye.
It's not a silly question. Whether or not you learn to dive depends mainly upon how severely affected you are by your fears of being harmed by some big fish or predator. If you cannot get these thoughts out of your mind while diving, then you may not be able to do the many tasks that you're expected to during a dive.
We become visitors in the ocean when we dive for very brief intervals. The fish live there all the time and it is their world. Very few of these creatures pay us any attention whatsoever, and if they do, it is usually to get out of our way. Shark attacks on divers are very rare. In fact, for the 10-year period from 1987 to 1997, DAN reported no deaths from shark attacks in its annual report on diving fatalities.
You should wait at least 12 hours after a single dive or 24 hours after multiday, repetitive diving to drive higher than 1,000 feet. If you can't wait, then you should treat your drive over mountains as you would a rescue flight (the Undersea and Hyperbaric Medical Society recommends waiting 12 hours). Rescue flights for people with a diving accident should not ascend higher than 1,000 feet, so that the victim is subjected to the least possible pressure reduction and to limit any further gas expansion. The same would apply to driving across a mountain range.
years ago, I
took a dive
trip to South Bimini. We
Your pilot was probably correct
diving pattern had
Therefore, we need to allow a
To answer your friend's
In two of his books on diving,
that we "should
The most recent guidelines concerning flying after diving are:
A minimum surface interval of 12 hours is required before ascent in a commercial aircraft.
beyond 12 hours after daily, multiple dives for
several days or
The deeper or longer the diving, the longer the duration recommended before flying.
These guidelines are for
should not apply
to commercial diving or nitrox diving.
DAN is in the midst of a study
All reported cases of DCS after a single
There are no guidelines concerning the time to dive after flying or having alcoholic beverages. However, mild dehydration can occur on long flights and alcohol consumption (and drinking caffeinated beverages) contributes significantly to dehydration. Dehydration is a definite risk factor in predisposing a diver to decompression illness because the washout of inert gas (nitrogen, in diving) is less effective in a dehydrated individual. There are few dive trips that don't start out with a complimentary rum punch (often provided by the dive operator), and one free drink often escalates into several—on top of what you might have had on the plane during the trip. There is a small uptake of nitrogen back to sea level partial pressure upon descent and exit from the aircraft. Residual nitrogen is referenced to nitrogen tissue levels above normal sea level values and a flight at 8,000 feet cabin altitude would result in lower tissue nitrogen levels than sea level. On descent, tissue nitrogen pressure would simply return to sea level amounts.
We should expect to see more decompression illness on the very first day of diving if there were a relationship between flying and drinking alcohol before diving. The Divers Alert Network (DAN) has reported some data suggestive of an increase in decompression accidents on the first day of diving of a trip. Their figures show that of the 88 cases reviewed from the Caribbean for 1994, 33—or 37.5 percent—occurred on the first day. The remainder occurred on days two through seven. These numbers are far too small to establish a cause and effect, but are suggestive. It would certainly seem reasonable to wait at least 24 hours before diving, rehydrating yourself as much as possible and avoiding overkill with the alcohol.
course, I learned of a change to the PADI open-water
dives after scuba
diving should be avoided because residual nitrogen
has made a
change to its
training, has there also been a change in the school
Important clarification: PADI
that the optional
open-water skin dive be done after the
As fas as your concerns about
decompression illness from breath-hold
I take interferon and
which are used to
treat hepatitis C. Should I be concerned
There are many different stages
and it would
be impossible to tell you whether you can
Interferon can cause side
of a decompression accident. These can
The liver is affected by
hepatitis C and
in the early stages of the condition. An
I can think of two things that cause gas and bloating in a diver:
* Pressure from your wetsuit can cause gastroesophageal reflux, particularly if the suit fits poorly.
* As you descend, you swallow some air while clearing. This air is not a problem at depth, but when you ascend, it enlarges and can cause pain and bloating.
You might want to try to clear using methods other than swallowing. There are medications that a physician can prescribe designed to help eliminate gas.
To read more on this, go to www.scuba-doc.com/hrtbrn.htm.
with an ulcer that
has flared up to the point where I have been put on
Diving with an active ulcer is
due to the increased
possibility of stress and possible
If your ulcer heals before your
confer with your
doctor about continuation of medication
For more information: www.scuba-doc.com/hrtbrn.htm.
Q: I weigh
pounds and will be
donating one unit of blood for use in an upcoming
surgery. How long
I wait after
a simple blood test is taken to determine your
hemoglobin level and you
can request the
There is a
shorten the time
interval before returning to diving after blood
10 percent of
Blood donors sometimes experience anemia. For an in-depth discussion of the effect of anemia on divers, go to www.scuba-doc.com/overview.html.
After your surgery, you'll also need to find out when to resume diving—which would vary according to
the type of surgery, post-operative course and your surgeon's advice.
I have been diagnosed with a
anemia in which
the part of my red blood cells that carries
People with anemia, whatever
have an oxygen-carrying
problem. You should not dive if
Can I Dive With Leukemia?
Two years ago I was diagnosed with hairy cell leukemia. Since treatment, my blood counts have been normal. I feel great and was diving before this was diagnosed, with no problems. Is there any reason for me not to be diving now?
Congratulations on having had a great response to treatment. You should seek a physician knowledgeable about dive medicine to recertify you as fit for diving. The doctor will pay special attention to immuno-suppression and/or bone marrow suppression from the medication—with the possibility of anemia and lowered white blood cell counts. If you're anemic, you should not dive due to the dangers of a low oxygen-carrying potential and hypoxia at depth. Hemoglobin levels below 12 Gm/dl are dangerous.
Pulmonary changes from anti-cancer medications should also be looked for. If you are taking any other medications, such as a blood factor that stimulates the production of white blood cells, there can be mild to moderate bone pain, which might be confusing if there were the possibility of a decompression accident.
With normal blood counts and no evidence of immuno-suppression, your physician should be able to certify you for return to diving.
Patients who have had successful coronary bypass surgery, angioplasty or stents are generally given the OK to dive—if you heed a couple caveats and observe some limits on your diving.
As you probably have been told, you need to keep your weight and blood pressure under control and maintain an exercise program. You'll also need periodic exams by your physician. Take an exercise tolerance test. If you can exercise with no decrease in blood supply, chest pain or serious heart irregularity and have a normal blood pressure response, you can undertake limited sport diving—in warm water (wearing a 3mm wetsuit), at shallow depths (to 60 feet), in minimal current and with easy entry and exits.
I've Got a Weak Heart—Can I Dive?
condition is called
cardiomyopathy or "weak heart." I have gone from an
output of 15
information that you
have provided I would be very reluctant to allow you
to dive. This,
(cardiac irregularities) associated with
blocker, and as such, blocks the normal response
Simple immersion can cause pulmonary edema in some people.
can cause dehydration—a known risk factor for
can cause drowsiness and sedation in some
Bad news: You probably should not dive. I assume you are referring to "aortic stenosis," a congenital obstruction that prevents blood from getting from the left ventricle of the heart into the aorta. Any degree of this condition, other than extremely mild, is a contraindication for diving because the heart is prevented from pumping blood during exercise, and pulmonary edema and fainting can ensue.
Some divers who have hypertension that is well-controlled with medication, and who have no damage to the heart, brain, eyes or kidneys, can dive. They are usually admonished "not to dive too deep" by their physicians who know little about diving medicine. Cold water, heavy exercise and stressful situations can cause the blood pressure to rise precipitously, even in those on medication, and can result in heart arrhythmias, strokes or infarction. The biggest risk, however, is the strong relationship between hyperetension and coronary artery disease.
Although most hypertensive medications have little effect on diving, those that are called beta blockers can reduce the ability of the heart to respond to the stresses of diving, and can lead to heart failure. If you are not on beta blockers, have a normal blood pressure (below 140/90), and if you can pass the exercise treadmill test (13 METS, 4 on the Bruce scale), you should be allowed to dive.
However, this is subject to the
Can I Mix Hypertension Medication With Diving?
I have high blood pressure and am taking 10mg of Vasotec daily. I am also taking 10mg of Lipitor for cholesterol. I recently tried to take a resort course in Cancun, Mexico, but was denied because of the medications I am taking. I am currently taking a scuba class at my local community college. Can I dive while taking these medications?
People with controlled hypertension (less than 140/90) are usually allowed to dive if there is no damage to the eyes, brain, heart or kidneys. Hypertension affects whether a person can dive because it is a risk factor for coronary artery disease. For this reason, it is recommended that all hypertensives, and anyone over the age of 45, have physicals to ensure their fitness to dive. Divers should have an annual exercise stress test to make sure that they can exercise to a sufficiently high level to participate safely in diving. An acceptable, or satisfactory, result on a treadmill exercise stress test means that the person is able to complete at least six minutes of the standard Bruce protocol without chest discomfort or significant electrocardiographic (EKG) changes that would indicate coronary artery disease.
The type of medication prescribed to treat your hypertension must be factored into the decision. Of particular concern is the class of medications known as beta-blockers, which can limit your ability to achieve the level of conditioning necessary in an emergency situation, and diuretics, which can dehydrate you and increase the risk of DCS. Other anti-hypertensives have few adverse effects on the diver. Vasotec is an ACE inhibitor and has some significant side effects (listed at www.rxlist.com/cgi/generic/enalap.htm#sect-Contraindications). These include hypotension and cough in some people. This would not preclude diving if these are not severe. Lipitor has no side effects that would adversely affect diving (www.virtualdrugstore.com/cholesterol/atorvastatin.html).
Another concern is the type of diving you do. While it is certainly true that reef diving is less strenuous, and probably less dangerous than diving in cold water or swift currents, there is still some risk. Every dive must be considered potentially strenuous. You must have a sufficient amount of physical reserve beyond what the planned dive requires in order to cope with unexpected situations or changing environmental conditions. For this reason, I suggest that divers demonstrate that their hearts can handle more than the minimum amount of necessary exercise before being cleared for diving (13 Mets or 4-5 on the Bruce scale).
See your doctor, have a physical and an exercise stress test, and if you're cleared to dive, enjoy!
Can I Dive With a Pacemaker?
I was born with a congenital heart defect between the ventricles and the atrium. I now have a pacemaker that regulates my heart at 60 beats per minute at rest. The maximum rate is set at 120 beats per minute, but that rate is uncomfortable for me and produces anxiety. Can I dive? Are there special considerations I should know about?
Generally, people requiring pacemakers should not dive because of their basic heart condition. Occasionally there are individuals with certain arrhythmias who have pacemakers who may dive. If no other heart disease is present, and the pacemaker is tested against pressure up to 130 feet and exercise tolerance is good, you might be able to dive. However, there are pacemakers that increase their rate when pressure is applied to the generator case, resulting in a heart rate inappropriate to the demand.
Unfortunately, it's impossible for me to advise you properly without a cardiologist's evaluation of your condition. For more information on pacemakers, go to www.scuba-doc.com/pace.htm.
Thrombosis in finger
I recently suffered a thrombosis in my finger. I spent five days in the hospital on Heparin (a blood thinning drug), and underwent a whole load of tests including an angiogram. Everything was fine. I now take an aspirin daily and have given up smoking. I asked the doctors if my condition poses any problems for diving and they said no, but I'm worried they really don't understand diving. Does it cause any problems? My second question is this—I had been diving six weeks prior to suffering the thrombosis. Could it have been an air embolism, rather than a blood clot?
It would be highly unlikely that this is due to gas embolism at this late date after diving. Your diving could possibly have something to do with the thrombosis, however, since cold will sometimes trigger a Reynaud's type phenomenon. Good to hear that your tests are all normal and that you have quit smoking. Diving with aspirin is OK, and possibly even acts as a preventive for decompression sickness.
for a deep vein thrombosis (DVT) in my leg. Will
Diving with DVT could be
effect of dive equipment, belts and
Secondly, the drug Coumadin is
to control and
dangerous because it makes it possible for
For more information: www.scuba-doc.com/antcoag.htm.
sickness and entered a recompression chamber for
Treating decompression illness
sickness and arterial
gas embolism) is just one of the
Being compressed in a chamber
"dry dive" without
the dangers of being in a watery, alien
Some side effects of hyperbaric
seizures and lung damage from oxygen
Your continued problem may be due to several factors. First, you may still have some of the nematocysts in and on your skin. These will not only cause problems from the toxins but can cause an allergic reaction. Secondly, you might have developed a chronic dermatitis to the proteins and histamines in the toxin.
Dr. Bruce Miller, a consultant to "Diving Medicine Online," says that it would be wise for you to seek the advice of a dermatologist for possible systemic treatment with antihistamines or steroids.
- via email, Los Angeles, Calif.
You could have brushed against some fire coral, though fire coral is usually reddish-orange with white tips. In any case, you were definitely stung by the nematocytes of a marine organism. The nematocyte is present in hydroids, fire corals, jellyfish and many other ocean creatures. It fires a toxic dart when it comes in contact with the skin, leaving a reddish welt that stings, burns and itches. Scratching, rubbing or applying fresh water makes more of the nematocytes fire and worsens the problem.
Your wife could have encountered sea bather's eruption or sea lice. This is caused by coming into contact with the larvae of the thimble jellyfish or nematocysts (the discharge from the nematocyte) from several other ocean organisms, which abound in Caribbean, Gulf of Mexico and Florida waters at certain times of the year. It usually has a local name, such as aqua mala, but is caused by the nematocytes of jellyfish, hydroids or anemones.
It most often affects the skin under the swimsuit, around the edges and in skin creases, and recurs if the suit is not rinsed properly.
Treatment of both your conditions
taking an antihistamine
for the itching and applying an over-the-counter
percent) to the rash areas. More serious eruptions
systemic steroids and steroid cream.
burn about a
week ago. I treated it with vinegar, meat tenderizer
Coral can cause rashes from four sources:
You seem to have a combination
three. The first-aid
measures you took are appropriate for
Persistent difficulty usually
foreign body particles
related to the abrasion. A visit to a
For more information, go to:
It's not true. There are no air bubbles at the base of the brain, and diving after 50 years of age requires no depth restriction to 40 feet.
There is some indication that as we age we are more prone to a decompression accident, but this requires only a sensible reduction in depth and time at depth, with conservative ascents and safety stops.
It is likely that you were coming down with an upper respiratory infection prior to your dives and the dives had nothing to do with your serious problems with bronchitis and asthma. If you were breathing continuously during your ascents you should have had no problem with pulmonary barotrauma. Barotrauma doesn't bring about asthma; it's the other way around. Lung overexpansion injury would have caused other symptoms that would be readily apparent to your doctor.
There are documented cases of pulmonary problems from fungus, mold and bacteria that are in gear that has been kept in a moist environment without cleansing prior to diving. This would be worth checking into in your case since your illness seems to be more than just a common cold.
Finally, ask your doctor to check into the possibility of foci of infection in your nose and sinuses that might have been transferred to your bronchi and smaller airways by the positive pressure of the regulator. It also would not be wise to dive until this has been sorted out and you show no evidence of asthmatic bronchitis or small airway disease, again as determined by your doctor.
For more information:
What Causes a Wet Cough After Diving?
I am a new diver who has no history of asthma or any respiratory problems. During my fifth dive, in cold water (62F) at 35 feet, I became cold and developed a cough that was wet. On surfacing, my breathing was very wet and rattly for hours afterward and the cough persisted until the next day. This has not happened before. I am a healthy and fit 40-year-old woman.
What you are describing is most likely pulmonary edema, where the lungs suddenly fill with liquid. This is seen in patients with heart failure, though in swimmers and divers it is usually not associated with heart disease but with other factors. However, before you do any more diving it would be wise to visit a cardiologist and be sure that you don't have a heart problem that you don't know about.
Pulmonary edema is unrelated to gas embolism from pulmonary barotrauma or decompression accidents. Contributory factors include immersion in water (particularly cold water), heavy exercise, negative pressure breathing and predive fluid overload. Symptoms and signs usually resolve spontaneously over 24 hours. Pulmonary edema can recur, so you'll want to avoid the factors that can contribute to it.
For more information: www.scuba-doc.com/puledem.htm.
Q: A close
of mine, who is
sick of hearing all my cool fish stories, wants to
he's had one of
A: I strongly recommend that your friend not dive. Points for him to consider very seriously:
A primary collapsed lung (spontaneous pneumothorax) usually is caused by underlying cystic lung disease.
There is a recurrence rate of 33 to 50 percent.
A secondary collapsed lung is caused by many diseases affecting the lung (e.g., asthma, scleroderma, tuberous sclerosis). The most common underlying cause is chronic obstructive pulmonary disease (pulmonary emphysema).
collapsed lung occurring under water will increase
size on ascent, causing a serious
procedures called pleurodesis
(scarring the lung surface) and pleurectomy
(excision of the pleura, a
The following are absolute contraindications to diving:
Diving within three months after any type of collapsed lung.
Spontaneous collapsed lung in beginners.
Expert divers with recurrent collapsed lung after pleurectomy.
Relative contraindications to diving include:
a collapsed lung (three years in case of
Divers with normal pulmonary function (determined by a variety of tests).
friend to take up
snorkeling so that he can enjoy the reef and seeing
What Are the Risks of Diving in Shallow Water?
Are there any risks associated with taking a scuba diving lesson in a 12-foot pool? Do the same rules concerning flying after diving apply?
There are some risks. A diver can suffer a gas embolism in as little as four feet of water. This happens when a diver ascends while holding his or her breath and has a collapsed lung.
While there is very little chance of a diver developing DCI from lessons in a pool, commercial divers who spend a great deal of time in shallow water or who make frequent repetitive dives in shallow water are at risk for DCI.
The risk to a diver who flies after short dives in shallow water is proportional to the time spent at depth and the degree of nitrogen saturation. If your dive sessions are lengthy, flying immediately after diving might place you at some danger of bringing bubbles out of solution during an airplane's ascent.
Can you recommend a seasickness medication that works but doesn't cause drowsiness?
- via email, St. Petersburg, Fla.
It's difficult to say what would be the right medication for you, as there are so many variations in the way individuals respond to medicines. What works for one person might not work for the next, and what makes one person very sleepy might not make another person sleepy at all.
Having said that, it's hard to beat the scopolamine patch (available under the brand name Transderm Scop), which tends to treat seasickness effectively without causing drowsiness.
One feared effect of diving with the scopolamine patch has been that there would be an increase in the absorption of the medication from the patch due to increased pressure at depth. But I haven't been able to find evidence in any medical literature that would indicate that this is a problem or even that it happens at all.
It has been my practice to advise the use of the patch for several days before diving to ascertain the effect of the drug on the individual. This allows for reduction in the size of the patch in case of any unwelcome effects.
I Throw Up Every Time I Dive!
I become nauseated every time I
up into my regulator.
I feel like I have altitude
There could be several things causing your nausea:
depth while clearing
your ears can cause nausea without other symptoms.
I am a new diver who has made about 20 dives. About 75 percent of the time, I get nauseated at the end of a dive. This has occurred in fresh and salt water, shore and boat dives. I am a healthy male and work out five times a week. Any suggestions?
via email Birmingham, Ala.
What you are describing is possibly vertigo and may be due to some abnormal stimulus of the balance mechanism in your inner ear. This can occur from unequal pressures between your ears (alternobaric vertigo) or can be due to unequal temperatures in the ears (caloric vertigo). In addition, there are other possibilities, such as air swallowing with enlargement of the gastric bubble on ascent or carbon dioxide retention. Also, tight belts and gear and wave action at the surface cause some people to feel nauseated.
Since there are so many things that can cause these situations in divers, it would be wise for you to see a diving-oriented ear, nose and throat specialist for a checkup. If the exam is OK, then consider that carbon dioxide retention might be your problem, and alter your breathing patterns.
For more information, go to www.scuba-doc.com/entprobs.html.
Two years ago after a weeklong live-aboard trip, I experienced "land sickness"—some dizziness, feelings of motion and slight nausea for four days. I am going on the same trip again this month. Any tips on prevention?
- via e-mail
We haven't heard it called "land sickness," but the situation you describe is an adaptation of the vestibulo-ocular reflex. When you get off a live-aboard, it can feel like you've just gotten off a spinning merry-go-round. This interesting phenomenon affects most astronauts and seafarers, at least to a small degree. The vestibulo-ocular reflex is a complex mechanism, but, basically, we'd have blurry vision if it didn't exist. This reflex is one of the most rapid, accurate and adaptive mechanisms in the body. It's what allows wild animals to stay fixed on prey while hunting at top speeds, Gail Devers to see the finish line while straddling hurdles at full stride and teenagers to see 'NSync on the stage while bouncing around during a concert. Your condition is a lingering effect of the constant visual motion you were used to on the boat and your body is taking a bit longer to return to normal. It can last up to several weeks. Unless prolonged or severe, it should resolve without treatment.
Spinal Cord Injury, Diving?
Is It Safe to Dive with a Spinal Cord Injury?
Nearly a year ago, I fell from a utility pole and sustained a serious compression/burst fracture of my T12 vertebra. After months of pain and physical therapy, I am back to work and trying to resume normal life. The only time I am truly free of pain is when I'm diving, but my doctor recommends that I discontinue diving. I get some carry-over relief after my dives that can last for days. Also, I take no medication for pain other than an occasional Tylenol. Is there therapeutic value from diving for people with similar injuries?
It is possible to dive after suffering a spinal cord injury, as long as there is no permanent damage. In your case, however, I agree with your treating physician. There are several concerns you should be aware of:
# A possible link between spinal cord decompression sickness after spine trauma.
# The disruption of blood supply to the area where the fractures occurred or surgery was performed—the formation of scar tissue and altered blood flow may not allow for the most effective off-gassing of nitrogen from surrounding tissue once it is absorbed during the dive.
# If there is any neurological damage and the diver suffers a spinal bend when diving, recompression treatment is likely to be more difficult and there will be greater residual deficit after treatment.
Generally, a sport diver can return to diving after complete healing and no evidence of neurological deficits as determined by a good neurological examination. This, of course, depends upon the type of surgery, findings at surgery and a host of other intangibles that can only be determined by your surgeon or neurologist. Your doctor's advice not to dive could be based on sound surgical reasons or it could be simply due to a lack of information about diving fitness qualifications.
Divers with back problems require careful assessment keeping in mind the heavy lifting a diver may be required to do when out of the water. A person who has had successful surgery with a normal neurological exam can be acceptable to be certified as fit to dive.
There is some evidence that back surgery disrupts the venous plexus of vessels around the spinal cord. This has been posed as a possible problem with the accumulation of bubbles and subsequent DCS. However, this has not been proven.
Two weeks is quite reasonable. Arthroscopy causes minimal trauma and very little alteration of the blood supply of the joint, thereby reducing the chance of joint damage from bubbles. The gas used during the operation in the joint is rapidly absorbed and poses no threat from barotrauma. You should record the degree of pain and discomfort in the knee before you dive in case there is any question regarding a decompression accident affecting the joint.
It depends on the type of surgery you have—abdominal, which requires two incisions, or vaginal, which requires only the vaginal incision. Healing of these is highly variable but usually require six to eight weeks before returning to full activity. Couple this with the need for conditioning, complete wound healing and the possibility of need for blood regeneration, and a period of eight weeks would be advised before diving. A post-op hemoglobin determination should be performed, and if it shows you are anemic, you should have that corrected before you dive.
Complications might include wound disruption, hernia and hypoxia from anemia. There would be no effects from the increased pressures of depth. There might be an increased risk of deep vein thrombosis due to the increased coagulability following major surgery and tight- fitting gear and wetsuits, but this is conjectural.
What is the recommended recovery time before diving after a vasectomy?
A vasectomy is a simple operation that consists of a small scrotal incision and removal of a small section of the vas deferens. Diving can generally be resumed after these operations when the incision or incisions have healed without scabs, or when you are cleared by your surgeon. Diving itself will have no effect on your surgery nor will the operation have any effect on your diving.
Vasectomy Does Not Increase the Risk of Prostate Cancer
Researchers from the Fred Hutchinson Cancer Research Center investigated how a vasectomy impacts the risk of developing cancer. They interviewed and reviewed the medical records of 735 men with prostate cancer and 703 men without prostate cancer. They found that the percentage of men in each group who had vasectomies was similar. The evidence suggests that vasectomy is not associated with an increased risk of prostate cancer.
Cancer Epidemiology, Biomarkers & Prevention (October 1999)
Teens are not more susceptible to decompression accidents. There are several caveats, however. Boys this age have narrow hips and are vulnerable to weight belt slipping during suit compression, even at relatively shallow depths. Moreover, says Dr. Maida Beth Taylor, consultant to "Diving Medicine Online," boys fuse their epiphyses later than girls. The epiphyseal plates near the ends of long bones are the major sites of new bone growth during development, and are very susceptible to injury or damage. If a DCS event occurred, it would be more likely to damage long bone growth in a boy of 16 than a girl who has completed her skeletal development and growth.
Physical maturity is one thing, intellectual maturity is another. Being physically able and comfortable with the heavy gear can be a real problem with a child's buoyancy, one of the most important skills in safe diving. Having the mental capacity to understand the physics involved in safe diving and the appropriate maturity for the decision-making that is required for himself and for the possible rescue of his buddy is something that most 15-year-olds possess.
Except for these caveats, there is no evidence that diving would affect the 15-year-old diver any differently than adults.
For more information: www.scuba-doc.com/teens.htm.
facility in Canada.
Now that there are courses designed for kids as
You pose a very good
There is no way possible for a
Physically, the young diver
minimum of 108 pounds
(50 kg) and be at least 60 inches
Cold stress and buoyancy
problems for a
person of smaller stature, particularly on
For more information on issues affecting young divers, go to:
There are no repellents that are 100 percent effective in preventing insect bites; if you only got 30 bites in five days in the Dominican Republic, I"d say that the Off! was 95 percent effective. Your choices:
DEET: N,N-diethyl-3-methylbenzamide (better known as DEET) is the most effective and best-studied insect repellent currently on the market and is the active ingredient in Off! When DEET-based repellents are used in combination with permethrin-treated clothing (see below), protection against bites of nearly 100 percent can be achieved. Plant-based repellents are generally less effective than DEET- based products.
HourGuard: The 3M Company developed a slow-release, polymer-based product named HourGuard that contains 35 percent DEET; this is the repellent used by U.S. military personnel. It's distributed by Amway Corp.
Skin-So-Soft: No-see-ums and sand flies use a different method to achieve their blood-sucking—by chewing the skin with mouth parts and an anti-coagulant. This is the reason sticky skin creams are effective at preventing their bites. Avon Skin-So-Soft can be mixed with Off! in a spray bottle, and is fairly effective, though not 100 percent effective. Avon now markets products under the Skin-So-Soft label that contain an EPA-recognized repellent. These products have very short half-lives and are also effective against some mosquitoes.
Bite Blocker: Bite Blocker is a plant-based repellent that combines soybean oil, geranium oil and coconut oil in a formulation that has been shown to be nearly 100 percent effective against mosquito bites.
Permanone: Permethrin (one common brand name is Permanone) is usually sold as a spray; it does not use DEET or citronella. It is sprayed on clothing, insect nets and the like (it is not applied topically). Permanone is found in outdoor sports and fishing/hunting stores and catalogues.
Bug Spray Verdict
No repellents are 100 percent effective. See above to find out just what these strange substances are made of and how effective they are alone or in combination with each other.
The quick answer: Don't dive while you're pregnant. We don't have very good data showing that hyperbaric pressure harms the fetus, and in fact, there are case records of hyperbaric oxygenation treatment of pregnant mothers with carbon monoxide poisoning without adverse effect on the fetus. However, the fetus does not have the protection of the lungs in filtering out the bubbles as does an adult.
All we can say is to stop diving if you are or may be pregnant. If you intend to become pregnant, please stop diving first. This is difficult advice, and surely some depths and times and kinds of diving must be all right, but no one can yet be sure what is safe and what isn't. The only thing that's for sure—anyone who tells you that certain limits are safe for pregnant divers is guessing, and may very well be guessing wrong.
According to Dr. Maida Taylor, "In this litigious society, there is only one answer—no diving while pregnant or even trying to conceive. No major studies prove it unsafe, but the hazards are there."
Breast feeding and diving?
I am breastfeeding my two-month-old infant and am planning my first weekend dive trip (I'll do four dives, average depth 80 feet) when my baby is four months old. I'll still be nursing then. I am a little concerned that nitrogen bubbles will get into my breast milk and cause possible harm to my baby.
There is some concern among divers who are nursing that their infants might be harmed by nitrogen bubbles in breast milk. Nitrogen does not seem to form bubbles in the milk located in the breast glands. Even if the nitrogen were in bubbles, it would do the infant no harm. Ingesting bubbles, even if microscopic, would in no way be harmful to the child, as they would reside in the gastrointestinal tract where gas is a prominent feature already.
However, there are other issues you should consider. Breast engorgement can occur during the dive excursion since I'm assuming you won't be able to breastfeed for at least several hours. This can be uncomfortable due to snug dive suits and gear straps. You may want to pack a breast pump so that you're able to alleviate any discomfort from engorgement.
There is also a possibility of transmission of marine pathogens from the nipple to the infant, causing a particularly stubborn infectious diarrhea. These same bacteria are fully capable of causing severe mastitis if the exposed nipple ducts and skin have any irritations or skin breaks.
Finally, Dr. Maida Taylor found that the combined energy expenditure of nursing and diving, and the associated dehydration related to immersion, caused a decrease in the amount of breast milk (Medical Seminars, 1998). Should this happen, be prepared to supplement with some formula approved by your pediatrician.
Given all these considerations, it might be wise to consider postponing diving until your baby is weaned.
Ernest Campbell, MD, FACS All Rights Reserved.