Dr Peter Wilmshurst has been a qualified doctor for over 25 years. He has served on the BSAC Medical Committee since 1977 and also advises the HSE on diving.
I have a problem with headaches after surfacing from dives. During the dive I feel fine, but when I surface I get a very bad headache, which can cause me to vomit. The headache comes on quickly, often as I surface. Any ideas

Headaches related to diving are common and can have a number of causes. Finding the cure in any one case depends on finding the cause in that individual, so further investigation will be required
    When we swim under water, we extend our heads back in a rather unusual position so that we can see forward in the direction in which were swimming. Its rather like looking up at the ceiling all the time. This puts tension on muscles and joints in the neck which can cause headache.
    Some divers bite too hard on their mouthpiece or have their mask-strap too tight, which can have the same effect. Anxiety on stressful dives can cause a tension headache.
    Carbon dioxide retention, which might be the result of problems with excessive equipment deadspace or inadequate ventilation of the lungs during dives, is another cause.
    Sometimes CO2 retention is the result of a deliberate attempt by a diver to reduce air consumption. Toxic effects of other gases can also cause headache, so it might be necessary to check both the diver and the equipment/breathing gas.
    Cold water can cause a headache identical to that which is triggered by eating something cold. This is known as an ice-cream headache. Further causes are sinus barotrauma and decompression illness.
We now recognise that some types of migraine after dives are particularly related to decompression illness. This applies particularly to divers who get migraine with aura (also called classical migraine) after dives.
    Migraine aura takes many forms, but the most common is visual disturbance, with zigzag lines or flashing lights either before, at the same time as or instead of the headache.
    Divers who get these types of symptoms, whether related to diving or not, are much more likely than others to have a cardiac shunt (or PFO) which will put them at risk of serious DCI, particularly neurological or skin bends.
Amputated fingers
I lost the tops off two fingers in an accident at work. The doctors say that the wounds should heal up soon. Are there likely to be any problems with the nerve endings, etc when diving

I do not anticipate any problems.

Return after Hodgkins Disease
Two years ago I was diagnosed with Hodgkins Disease. Until that point I was a PADI Rescue Diver and it was my Divemaster medical which detected the lump in my chest. I have now fully recovered, completing my treatment 12 months ago. Can I return to diving after chemotherapy , radiotherapy (below) and the chest surgery that was involved with my original biopsy

Radiotherapy to the chest and a surgical biopsy of lymph nodes in the chest could cause damage to the lungs which might predispose you to pulmonary barotrauma, though they probably will not. Before resuming diving, special tests need to be performed to make sure that the lungs have not been damaged in this way.
    If those tests are satisfactory, I believe that diving can be resumed.
Recovering from surgery
I have recently undergone surgery to repair an inguinal hernia. What is the minimum period before it is safe to dive

I have recently had my appendix removed. Can you advise me what length of time I should go without diving

It is important that after any type of surgery there has been complete healing of the wound to prevent dirty water getting in to cause infection. Healing will obviously be delayed if there is wound infection. The diver should also have regained normal full activity so that he or she is able to swim well.
    This will depend on the seriousness of the operation, the amount of pain remaining and the fitness of the individual. The operation itself must not be one that will affect fitness to dive, such as lung or ear surgery.
    Generally, for an operation such as an hernia repair or appendectomy, I advise laying off diving for six weeks, provided the surgeon is happy for it to resume at that time.
    Gentle and shallow work-up dives are recommended after any lay-off for medical reasons.
Check out the tube
On my second open-water dive I failed to clear my ear and perforated my eardrum. Will this limit diving once it has healed Will the ear be more susceptible to perforation under pressure

It is usually possible to dive once an eardrum perforation has healed, but your eardrum perforated on only
the second dive. This might indicate some problem with the Eustachian tube which interfered with pressure equalisation, so its important that this possibility is investigated before diving is resumed.
Diving without kidneys
I have a renal dialysis centre in Cornwall. One of my patients who has had both kidneys removed and is on dialysis three times a week wishes to return to diving. What are the implications of this Is there anyone diving who is on dialysis

There are people with kidney failure who are on dialysis diving. There are, however, a few things that need to be remembered. People with kidney failure have an increased risk of heart disease and high blood pressure, both of which can be a problem in divers, so it is important to make sure that such a diver has no evidence of heart disease or hypertension.
    This is particularly important because of the bodys way of responding when we are immersed in water, particularly cold water.
    When immersed, blood is redistributed from the legs to the trunk and particularly the chest.
The body responds to this in a number of ways, one of which is to reduce blood volume through production of urine.
    This does not apply in individuals with little or no renal function.
In that situation, there is a danger that the lungs will become congested and even overloaded with fluid (pulmonary oedema). This is a potentially fatal condition.
    For a diver on dialysis, the way round this is to start the dive relatively dehydrated, by taking a little extra fluid off during the dialysis before the dive. Alternatively, the diver with renal failure can take a drug that dilates blood vessels, so that central blood volume does not increase so much during the dive.
Anti-hypertension drug use
I take a drug called lisinopril for high blood pressure (20mg daily). Can I dive If not, what are suitable alternative drugs

Lisinopril belongs to the class of drugs called ACE inhibitors, which are good for controlling high blood pressure.
These are one of the classes of anti-hypertension drugs that we believe are safe for use in divers. If blood pressure is controlled adequately with lisinopril, diving can be permitted.