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.
My buddy suffers from trapped wind in his stomach after diving, and this causes him to belch for a long time. What causes this, and is it OK for him to carry on diving safely

Should I be concerned about diving, as I take nexium for reflux disorder I dont experience problems generally. I swim on a regular basis and sometimes do burp more than usual.

The stomach normally contains air, swallowed during eating and drinking. It is normal to burp to release excess gas.
During diving, several things contribute to the above problems. First, we swallow more air as we breathe through the regulator. Second, this gas is then subject to the same forces as all other air spaces in the body, namely compression during descent and expansion on ascent.
It therefore follows that as we ascend after our dive (and for some time afterwards) excess gas has to escape, either up or down. Reflux disorders are common, and are a result of a weakness in the inlet of the stomach. This allows food, fluid and air to come up into the oesophagus (gullet) easily and without warning.
This gas is often acidic and can burn the oesophagus. Drugs such as nexium are used to decrease the acid to reduce the damage but they do not cure the problem. As far as we are aware, they are safe in diving, but as with most drugs there have been no formal tests and their effects under pressure are largely unknown.
Reflux can be minimised by losing weight, stopping smoking and avoiding large meals before diving. There is a surgical operation to tighten the inlet of the stomach, but this often results in the patient being unable to belch or vomit. This is a contraindication to diving, as it may result in over-distension of the stomach, with subsequent rupture.
Asthmatic seeks job in diving
I am 16, and have had asthma since I was seven. I have never had a full attack, only the breathlessness, and am physically active. I am on Ventolin as a reliever but in the past two years havent had to use it. I am also on Seretide 50 as a preventer twice daily. Diving is about the only thing I want to be involved in career-wise, as a marine biologist or instructor. I have done a try-dive to 4m at a PADI centre abroad where they said I should be all right, and thoroughly enjoyed it. Can I dive with this condition

Asthma is one of the difficult conditions when it comes to diving. It can predispose towards air trapping and cerebral gas embolism (like a stroke). In the UK we have made great strides in allowing mild, non-exercise-induced asthmatics to dive. They must not show any closing of the airways on exercise or cold.
ÂPreventers (brown inhalers) are allowed, but regular usage of relievers (blue inhalers) indicate unstable asthma. Seretide contains a long-acting reliever and a preventer and is therefore not allowed with diving.
Potential divers who have asthma have their airways checked prior to exercise and after 15 minutes of hard exercise. Any closure of airways greater than 10% is a fail.
As far as marine biology is concerned, this will depend on the HSE. Divers who earn money from diving (as marine biologists do), come under Government regulations and are required to have annual medicals from an approved doctor. Diving with stable asthma may be possible if strict criteria are followed but again would have to be assessed at the time.
From your medication it doesnt sound as though you are stable enough to dive as yet , but this may change as you get older.
Your experience abroad is not unusual, and shows the potential danger that exists in some dive sites overseas - non-medically qualified people making fitness-to-dive judgments without proper knowledge or investigation. The fact that you dived only to 4m is irrelevant, as pressure changes are greater at shallower depths. Your first dive could have ended in tragedy.
Chain reaction
I broke my ankle last September and as a direct result developed a deep-vein thrombosis (DVT). This travelled to my lungs, causing a pulmonary embolism (PE). I was prescribed Warfarin for six months. In March the specialist gave me a test which involved blowing into a tube. She said the strength of my breath was normal and saw no reason why I could not begin diving, but advised me to check with a diving medical specialist. Do you see any issue with me starting to dive again

The DVT and PE were clearly caused by trauma. This does not give cause for concern, and you are also now off the Warfarin. PEs can damage the lung and unfortunately I do not have enough detail to know how your lungs were tested. I would consider full lung-function testing with flow volume loops and helium dilution studies (to exclude any air-trapping as a result of damage) as a minimum level of investigation for assessing you as fit to dive. It may also be necessary to undergo CT scanning if there is any suspicion of more major damage. You should contact your nearest medical referee.
Freshwater fears
Its a good idea to get a full set of jabs wherever you dive, but they won't prevent Weils Disease. Luckily its rare
I am planning on taking part in dives in the Thames and other British freshwater sites, both rivers and lakes. Are there any health risks involved in diving such sites What measures can I take to protect myself

I advise all British divers, regardless of where they dive, to have tetanus, polio, typhoid and hepatitis A and B vaccinations. This covers most bugs, but some cant be covered. The most important in lakes is leptospirosis, or Weils Disease.
This can give a nasty illness that can result in serious complications such as kidney failure, but there is no human vaccination for this.
Saying this, Weils Disease is rare, as Stoney Cove divers prove.
Make sure your regulators are well serviced to minimise aspiration, and to be really safe, do as the commercial divers do - wear a full-face mask.
Parkinsons dilemma
My friend has Parkinsons Disease. It is not severe, and he always passed the medical, but now a new doctor has told us that it is a contraindication for diving. My friend still feels able to dive, so should he talk to another doctor

Parkinsons Disease affects the brain of the sufferer and is caused by a lack of a chemical, dopamine, in part of the brain called the substantia nigra. It can cause symptoms as mild as slight tremor and some stiffness, or as severe as the inability to walk or move well, co-ordinate and even think clearly.
Many drugs are used to help and relieve symptoms, but the condition is not curable and usually progressive.
Without a detailed examination tailored to fitness to dive, it is impossible to say whether your friend can dive. At the mild end of the spectrum some limited diving would be possible, but as the condition progresses and medication changes, it might not be. Even at the milder end, I would anticipate some restrictions.
I dont know if this doctor is expert in diving medicine, or knows about disabled diving, but that is the sort you need to see for an expert opinion.
Burning sensation
Diving in Cozumel, my hand brushed against coral and I felt an immediate burning sensation. A week later I had a maculopapular eruption over the back of that hand. It is not spreading, but it is itching and is not improving with topical Hydrocortisone. Any thoughts

I do not profess to be an expert in coral injuries. My diving experience is mainly cold water, but I will attempt a reply.
Coral cuts are known to cause problems. As well as cuts due to sharp edges, they are covered in infected slime. There may also be problems related to discharging nematocysts.
Apart from the immediate risk of local infection, one sequel is a pruritus (itching), which can persist for weeks.
If this is your problem, it should respond to a local steroid ointment. Hydrocortisone is the weakest topical steroid - try a stronger one!