All divers love to dive, sometimes they do so in spite of themselves. The following are in the list of NOs for safe diving:
- Very serious head injury even in the remote past, epilepsy, active asthma, spontaneous pneumothorax, CNS (brain and spinal cord) disease, including tumours and previous CNS DCS, uncontrolled psychiatric disorders including drug abuse, very high blood pressure, heart failure and chronic pulmonary disease (including obstructive, tumour, infection or barotrauma).
- Patients suffering from any of the above do not usually go on diving trips (though I have seen people dive with each one of them), but some conditions can develop after a diver has planned the trip:
- Pregnancy is always contraindicated, for the safety of the mother and baby.
- Recent surgery needs individual evaluation. Simple skin sutures, as from a cut, are a common concern. One should wait a few days at least after suture removal. It is never a good idea to dive with an open skin wound as these will infect and fester easily.
- Respiratory tract and ear infections such as common cold or influenza. Also inability to perform the Valsalva manoeuvre (pop the ears).
- Traveller’s gastritis or diarrhoea, if severe, can also be a problem, and one should wait until fever and bowel motions have stopped.
- Acute alcohol intoxication is a common occurrence with divers! One should remember that even a couple of beers the night before carries a significantly increased risk for diving.
- Any form of severe psychological distress or anxiety (such as receiving bad news) is also a relative contraindication, as a diver under these conditions will not react well in an emergency.
- One of the most important and common of the relative contraindications is diabetes mellitus. If the condition is well controlled and stable, these patients can dive with relative safety. Different dive doctors give varying, sometimes complicated, advice. Personally, I like to advise the diver to do a single daily morning dive and omit the medication before the dive if their condition permits this. This eliminates the greatest single risk, which is a hypoglycaemic faint underwater. Divers with a history of ischemic heart disease (heart attack or angina) like diabetics need individual assessment. Some doctors will quote other factors such as gross obesity, deafness, blindness, physical handicaps or advanced age as disqualifying. I tend to disagree. As long as the diver/instructor knows their limitations well, these people can safely enjoy the sport too.