
I have been diving for five years and have done nearly 200 dives. I have always felt comfortable and never had any problems. On my last dive, not a difficult one (clear water, 19m, 23Ã‚C), while going over a large rock (maybe I went up fast) my heart began beating very fast and I felt dizzy. I had to stop and hold on to the rock. It lasted about two minutes. Should I be worried about this incident Vasco

The heart can beat fast for a number of reasons. Some are appropriate, such as the increase in rate caused by exercise and emotional stress, both of which can occur during a dive.
Other causes are abnormal conditions related to the dive or coincidental disease.
Because this problem occurred during an ascent, we need to consider the possibility of barotrauma. Other possible causes include disease of the heart or disease outside the heart, such as an overactive thyroid gland.
It is impossible to reach a diagnosis without a proper medical examination. You should therefore consult a doctor before diving again.
Coming out in a rash
In the last year I have noticed skin rashes on three occasions after diving. The dives were to between 20 and 32m. The itchy rash was on my hands and feet on one occasion, all over the body on another and just on the trunk on the third. I was told that it was caused by an allergic reaction, but could it have been decompression sickness

Skin rashes after diving may well be the result of a skin bend. Allergic reactions are another possibility. It is common for skin bends to affect the trunk, but not the hands and feet.
However, I feel that anyone who has had a rash after diving should have a contrast echocardiogram (a special type of ultrasound test of the heart) to exclude the presence of a patent foramen ovale or other type of hole in the heart, commonly the cause of a skin bend. If such a hole is present, there is a risk that a future bend will be neurological and cause paralysis.
Another thing anyone with this condition can usefully do is have someone photograph the rash before it fades. It makes it easier to diagnose. Try to get distant photographs to show the distribution of the rash and a close-up to show the details.

Treatment for hypertension
I am a 46-year-old male who has been prescribed Candesartan for hypertension. Are there any known concerns for recreational divers who use this medication to maintain healthy blood pressure levels Of the different hypertension medications, is Candesartan among the preferred treatments for divers

Hypertension is an important issue for divers, because high blood pressure is common and divers with raised blood pressure have an increased risk of diving-induced pulmonary oedema.
In this condition fluid passes out of the pulmonary capillaries and into the alveoli. The effect is similar to near-drowning. The diver becomes breath-less and may cough up froth and blood. In extreme cases the diver can die.
Good blood pressure control is important in hypertensive divers but does not rule out all possibility of this condition. Divers with high blood pressure need to be aware of this.
Good control can be obtained with many drugs and some are better than others for divers. Candesartan is a new one which works as an angiotensin II receptor antagonist.
Drugs in this group should be good for divers. In theory their method of action is such that they should reduce the risk of pulmonary oedema. However, we cannot be sure that they will not have adverse effects or side-effects in divers without a trial requiring drug treatment of thousands of divers over thousands of dives. All we can say is that there is no reason to believe that Candesartan is unsafe.

Chest and spine
I had spinal surgery following a motorbike accident. The surgeon put titanium rods, plates and screws into my back. He also performed a thoracotomy which required him to open the chest cavity. I have been told that it is unwise to dive after a thoracotomy. Is this correct

A thoracotomy, like any other form of injury to the chest, is thought to increase the risk of scarring in the lungs, which will increase the risk of pulmonary barotrauma when diving. The actual level to which that risk is increased depends on the amount of damage done to the lungs, and this can be tested.
Putting this in context, a smoker
may be at greater risk of pulmonary barotrauma when diving than many individuals who have had a thoracotomy that produced little trauma to the lungs, but we do not prohibit all smokers from diving.
As a minimum, those who have had a thoracotomy should have lung-function tests and a chest x-ray before returning to diving. A CT scan of the chest may be needed.
The spinal injury is another issue if there has been damage to the spinal cord itself and not just the bone. 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.

Ear solution
I am 52 and have been diving only for about six months. The day after a dive in a reservoir, my ear began to ache and my doctor diagnosed otitis externa. Antibiotics cleared the infection but it recurred after another dive. I am told that aluminium acetate ear drops might help prevent a recurrence, but my doctor has not heard of this treatment.

Otitis externa is inflammation of the outer ear, which produces itch, weeping and pain in the ear canal. It can be caused by infection or allergy.
Aluminium acetate ear drops (usually a solution of aluminium acetate in weak acetic acid) is an excellent drying agent. A drop or two in each ear after a dive desiccates and kills any organisms carried into the outer ear canal.
This is useful for preventing otitis externa or coral ear. Try a chemist such as Boots, though it might have to send off to have the prescription made up if it doesnt hold the raw materials.

Bone Necrosis
The UK Sport Diving Medical Committee has released this statement:

Bone necrosis is a serious disease of bones, also called avascular necrosis or dysbaric osteonecrosis. It has a number of causes but exposure to hyperbaric conditions is the usual reason when it occurs in someone who dives or has dived.
Until recently it was thought to be an occupational illness occurring only in professional divers and caisson workers. However, in the last few years the members of the UK Sport Diving Medical Committee have become aware of cases occurring in amateur divers and wish to bring this condition to the attention of all amateur divers. The disease can occur months, years or even decades after hyperbaric exposure.
In essence, the disease causes areas of bone to die. If these dead areas are next to a joint, this can result in severe joint damage and may necessitate joint replacement. When a dead area affects the shaft of a bone it causes no symptoms, but there is still cause for concern because bone necrosis can change to a form of bone cancer.
The cause of dysbaric osteonecrosis is unknown. There is no proven association with decompression illness, though both can affect joints and the risk of each condition is related to the degree of exposure to hyperbaric conditions.
The incidence increases with the depth of dives, their duration and the number of exposures. Amateur sport scuba divers were considered to be at low risk because their dives were usually short and shallow, but as they go deeper for longer and use gas mixtures containing helium, it is probable that more cases will come to light.
Failure to learn from past lessons may cause amateur divers to suffer an epidemic of bone necrosis, similar to those in caisson workers in the last century and in professional divers earlier this century, before safer work practices were introduced to those occupations.
The committee has been sufficiently concerned to set up a registry of cases. Divers in whom bone necrosis, avascular necrosis or dysbaric osteonecrosis has been diagnosed are asked to write to Dr Peter Wilmshurst at Royal Shrewsbury Hospital, Shrewsbury, 5Y3 8XQ.
Individuals who have not had this diagnosis made by a doctor should contact their own doctor rather than writing to the registry.