Headaches and diving
Honey-glazed memories of summer have been rinsed away by autumnal rains; and the trickle/flurry of wintery party invites has commenced. With the season of good cheer fast approaching, the shadowy spectre of the industrial-strength hangover looms large on the blurry horizon. So an article on headaches and diving seems appropriate. Not that most are alcohol-related, of course; the causes are numerous, varied and sometimes difficult to disentangle. One paradox in diagnosing headaches is that despite the head being full of nerves, it is very poor at localising pain. Quite often the site where pain is felt is far removed from the actual cause. A good headache history is required, and my preferred way is to analyse the time course.
Poor fluid intake, hot weather, diarrhoea, vomiting and breathing dry compressed gas all contribute to dehydration (the most overlooked yet easily treated cause of headaches – drink, drink, and then drink some more). The headache we associate with a skinful of booze is down to three main effects. Firstly, alcohol directly dilates blood vessels in the brain. It also causes us to excrete large amounts of salt and water, thus leading to dehydration. And finally, the congeners – not a daftly-named tribute band, but the by-products of alcoholic fermentation, can impart a hammer blow to the cranium (Different drinks contain different congeners, which is why mixing them often results in particularly severe hangovers). Anxiety and muscular tension are common, and if there’s any pre-existing neck or back problem, all of the above can be exacerbated by a bumpy boat ride, carrying a heavy tank, etc. Ideally we should all have a good hard massage before each dive – any volunteers?
There can’t be many divers who’ve never suffered an ear or sinus squeeze, and typically these will occur on descent or ascent, i.e. when trapped gas is contracting or expanding. The pain can be excruciating and felt locally (e.g. over the eye [frontal sinus] or cheek [maxillary sinus]), or sometimes more diffusely (e.g. over the top of the head if the sphenoid or ethmoid sinuses are affected). These pains tend to resolve within half an hour or so once back at sea level, and slow, careful equalising in the absence of respiratory congestion is essential to avoiding barotrauma in the first place. Loosening mask straps is a simple but surprisingly effective cure for some generalised headaches, as is relaxing one’s bite on the regulator mouthpiece – the beginner’s constant vice-like grip is a good recipe for temporal headaches. And a cold head is never comfortable, as I know only too well. A nice thick hood for the follicularly-challenged among us is always prudent.
Excessive exertion on deeper dives can result in a build-up of carbon dioxide, which may cause headaches and dizziness during and for several hours after a dive. Slow, relaxed, deep breathing is the key to resolving this. If headaches are accompanied by odd neurological symptoms (visual disturbances, numbness, tingling, weakness, etc), then we have to consider migraines or DCS as possible causes. The former will often be associated with a history of prior headaches, and possible dehydration as a trigger factor. Missed safety stops, rapid ascents, repetitive deep dives and the like swing the diagnostic pendulum more towards DCS. Either way, this sort of presentation needs full and rapid assessment by a dive doc, preferably at a chamber.
So, to sum up: chill out, relax your neck and mouth, stay warm and well hydrated, breathe deeply and slowly, dive shallow and short, avoid recreational drugs, and with any luck your headache will miraculously evaporate. If not, it’s off to the doc’s for a proper going over.
Full article in December’s Sport Diver