Dr Ian Sibley-Calder has been a GP since 1988, is a medical referee for the UK Sports Diving Committee and is involved with hyperbaric medicine and commercial diving activities. He is a BSAC Advanced Diver and Club Instructor.
Flexibility exercises are vital in maintaining the fullest range of movement
I am 23 and suffer from Ankylosing Spondylitis, so I experience occasional restriction in the movement of my chest wall and the associated stiffness of the lower back and hips. Im fairly fit and well otherwise, and have been told that exercise is essential in managing the case, especially swimming. My concern with the limited chest expansion is the weight of diving equipment on my back - is it possible to continue

Ankylosing Spondylitis is an inherited condition that affects both males and females. Females are usually affected only mildly, with low back pain, but males can be severely affected. In extreme cases it can result in total fusion of most of the spine into a solid, inflexible rod. Most people are not affected this badly, although restriction in movement can occur.
Other effects such as inflammation of the aorta (main blood vessel out of the heart) can uncommonly occur. The condition can be controlled by medication but flexibility exercises are vital to maintain mobility and spinal movement.
Equipment problems can be tackled by imaginative use of devices such as weight harnesses, but youre right to be concerned with the limited chest expansion. If the chest cannot move well, your exercise tolerance will be reduced and potentially could result in reduced tidal flow and carbon dioxide retention. There should also be no evidence of air-trapping.
This is easily settled by a visit to a doctor interested in diving medicine who can undertake detail lung testing and review your exercise performance. The doctor would also have to assess medication in respect to fitness to dive. This would have to be a regular check-up, as the disease is progressive.

I cant stop peeing
I seem to pass urine rather frequently during a dive - should I be concerned I do drink plenty, especially in tropical climates.

This is simple physiology. It relates to several factors, but primarily to immersion in fluid and the hydrostatic pressure on the body, and to cold.
When we enter water, the pressure all round the body (and the cold) squeezes the fluid into the blood vessels.
This tricks the body into thinking it has too much fluid on board, and so we pass lots of urine. When we surface, we are therefore dehydrated. This occurs routinely on all dives.
This is important, particularly in hot climates, as it can increase the risk of decompression sickness and was thought to contribute to the large rise in incidents in the hot summer of 2003.
It re-enforces the need to maintain good hydration, with plenty of regular clear fluids and rehydration drinks.

Diving after a brain injury
As a speech and language therapist, I work with people who have had brain injuries. One person would like to dive again, but is such an injury or stroke a bar to diving

This is too difficult a question to answer in this way. Fitness to dive would depend on many factors related to the disability of the diver, any evidence of epileptic fits and medication.
Any person in this situation would need to be assessed in an individual way by an experienced diving doctor. I would imagine that some individuals could restart diving under a disabled diving scheme after full assessment.

src="http://diverfiles.net-genie.co.uk/data/archive/medical/pics/1204medqna2.jpg" Not even the suit manufacturers know whats in neoprene
Allergic to neoprene
I enrolled on an Open Water course in January and was ready to dive when I developed a very bad allergic reaction to my neoprene wetsuit, to the point where I had to take oral and topical steroids. I know I could use a drysuit, but in really cold water I will need a neoprene hood and gloves. I also want to dive in warmer climates, so have you heard of any alternative to neoprene

Arrange with your GP to go for patch-testing by a dermatologist to find out to what exactly you are allergic. This will make it easier to find out what to avoid.
Mostly likely you are allergic to one or more of the chemicals that make up the neoprene. The problem is that even the manufacturers dont always know what exactly is in their neoprene. These chemicals also seem to cause more problems when the material is warm, so some people cope by staying cool and removing the suit as soon as possible.
A membrane drysuit would seem to be your best option, though you may have to be careful of the boots. Some sort of plastic glove under the gloves and a light material hood under the neoprene should help.
Drysuits are used abroad, and I know several divers who will not dive in anything else. Just vary the amount of underclothing depending on heat.

Kidney problems
Is kidney failure a problem with diving The person in question suffered complete failure several years ago, had a failed implant and is now on dialysis. He wants to learn to dive.

I would regard this problem as not really compatible with diving. People on dialysis often have significant medical problems, as well as the constant need to regulate fluid balance and food. He should find another hobby, particularly as he has not yet started to dive.

src="http://diverfiles.net-genie.co.uk/data/archive/medical/pics/1204medqna3.jpg" Smoking and diving are incompatible, - and youll get your fags wet
Smoking and DCS
In past issues of , the idea of protecting against decompression sickness has been discussed. As a non-smoker, I wondered what your views are on smoking and DCS. Smoking makes platelets sticky, and therefore may increase risk of a bend. So increased hydration, exercise, and not smoking seems the best way of protecting against DCS.

Youre absolutely correct, there is suspicion that there is an association with smoking and DCS, though the risk is difficult to quantify. There is certainly an increased risk with smoking of lung disease and associated barotrauma-type problems (pneumothorax, CAGE).
Smokers also bind their red blood-cells with several per cent of carbon monoxide. This reduces their oxygen-carrying capacity, an effect which must be exacerbated at depth.
It must be like having a bad fill from a compressor on every dive, especially for those divers who insist on lighting up seconds before hitting the water. The advice, as ever, is to stop smoking.

Shallow narks
I have been diving for more than a year, and most weekends. I am female, 40, and seem to get a touch of narcosis after 15m or so. This is relatively shallow, and I was wondering if this is a sign that I am not fit.

Narcosis is related to an increased partial pressure of nitrogen in the tissues. This acts as an anaesthetic agent (like nitrous oxide or laughing gas) and affects everyone differently, but its effect is like drinking alcohol.
Just as some people seem to hold their liquor well, others get drunk on small amounts. Equally, though some seem to be all right, their performance can be affected without them realising it.
Most divers seem to notice the effects at around 30m but it varies from diver to diver and is affected by factors such as anxiety, cold, darkness, hunger etc.
As with drinking, tolerance by regular exposure can occur, but you are still affected. Accept it, but be aware of your limitations. As you get more experience and relax more, the effect may lessen.

What about Hep-C
I have Hepatitis C, with no symptoms or signs of the disease. My specialist tells me that because I rarely drink, dont smoke and maintain an active lifestyle I will probably die of something non Hep-C related. I have been a scuba diver for four years and recently decided to become an instructor. My dive shop refuses to certify me because it believes that a Hep-C case should not be diving. Is this true

If you are well, and not on any medications that could affect your health regarding diving, then Hepatitis C is not a reason to stop diving.
Hepatitis C is a blood-borne infection of the liver. In most cases, it is a smouldering infection that does not cause particular trouble, but in some unfortunate people it can ignite and cause cirrhosis and more serious effects.
Equally, some people are put on a cocktail of strong drugs which would need assessing before they were allowed to dive.
The main risk would be in transmission of the disease to others, but if sensible precautions are taken this risk is negligible, and should not stop training. Mouth to mouth contact is best avoided where possible, though even then the risk is low unless there is direct blood transmission.