Dr Jules Eden, dive medicine specialist and founder of e-med, answers divers' questions - as published in Sport Diver magazine:
Q - I have been diagnosed with Obstructive Sleep Apnoea and have been using a CPAP machine for 2 yrs. I am an open water diver and have never had a problem whilst diving. I have declared this on my insurance previously and had no queries, but have recently been asked to have a physician's opinion as to the effects of the condition with regards to diving.
I have trawled the internet for reports or evidence as to the safety (or not) of the condition but cannot find anything that even mentions OSA and diving at the same time. My GP is aware of the condition to a certain level, but is not familar with diving. I would appreciate your advice.
A - So when they talk about the "tired diver tow", that'll be you mate. Sleep apnoea, or to give it its other name Pickwickian Syndrome, after the fat geezer in the Dickens novel, is all about sleep. And being apnoeic. Put them together and you basically cannot breathe so well when you sleep. This decreases the oxygen to your body at night, so you wake up tired, as well as waking up through the night grunting as you snore. It's a problem that only occurs at night though.
So how does it affect diving? Well I suppose, as long as you are not so knackered in the morning that you can't think straight on a dive. Or as long as you are not expecting to sleep on a dive, then you will be OK.
The CPAP should cure it. Continuous Positive Airways Pressure. A tube up your nose blowing in air, to make you breathe, should reverse tiredness.
Dive on, sleepyhead.
Q - I wonder if you could give some advice, I am due to start a PADI course in Thailand next Tuesday however have unfortunately managed to get a cold which started yesterday as a sore throat which has now gone but left a blocked up nose. Do you think by next Tuesday it will be okay to dive?
A - You could be lucky here. If the cold has come and gone through that sore throat, swallowing razor blades, choking on a porcupine phase, leaving just a stuffed up nose, then this could clear in time for Thai diving. Only you will be able to tell on the day. The easiest way of telling is to stick your finger up your nose. If it comes out wet and mucousy, don't dive. If it's dry then off you go into the blue.
The problem with trying to dive with a cold, is that when you equalize, instead of air going up the Eustachian tube, its snot instead. This will fill the middle ear, and stay there for a good 6 weeks. Your hearing will be dulled and you'll hear every footfall echo in your head when you walk. However some people think this is a reasonable trade off for a certain dive experience. Others do not.
Medication like Sudafed is an option at times, but I prefer to use this for the flight out there, and if I get a snotty reaction to sea water. Not for a cold though, as it may not be enough.