HEALTH / Second Opinion

DOCTORS learn to identify the cause of someone's headache in much the same way as ornithologists learn to recognise birds: they can put a name to a pattern of symptoms because it is familiar. Headache specialists have spent more time headache- watching than their colleagues and so have become better at it. They are also interested in headaches and so are more likely to find how to relieve them.

Recognition based on system and experience might seem a somewhat old-fashioned approach to medicine, but in headache there are usually few other clues. The technical advances made in brain imaging using magnetic resonance and positron scanners, the discoveries in genetics and the unravelling of cell biochemistry have been no help at all in the diagnosis of most headaches: all the tests will be normal in 99 per cent of patients seen by a family doctor.

What, then, has a doctor to offer someone coming into the surgery complaining of a headache? The fact that the patient has come at all usually indicates that he or she is worried, though the anxiety (Is it a brain tumour? Have I got meningitis?) may be concealed. The rare serious disorders virtually always cause additional symptoms and abnormalities which are revealed by physical examination. Recurrent headaches with no other symptoms fall mostly into two main categories: tension headaches and migraine. A third type is the headache caused by overuse of headache tablets.

Half of all adults have tension headaches at some time, many repeatedly. Remarkably often the words used to describe the pain are the same: people talk about a band around the head or a weight pressing down. Sufferers often know what has brought the headache on - a poor night's sleep, a row at home, conflicts at work - but some may be unwilling to make the connection. Dealing with the headache by swallowing tablets may be reasonable if it happens only rarely, but frequent headaches of this kind should ideally be tackled by attention to the source.

Migraine headaches affect 10 per cent of the population. The diagnosis is usually obvious, since the pain is one-sided and associated with feelings of sickness and dislike of strong light. In classic migraine the headache is preceded by strange visual phenomena such as flashes or zig-zag patterns. Again the sufferer may know all too well what brings the headaches on - fatigue, too little or too much sleep, certain foods. New drugs such as Sumatriptan have made control of migraine headaches easier, but even so the best strategy is a preventive one based on identification of the lifestyle triggers.

Analgesic headache has become recognised as a common problem only quite recently. It may seem odd that tablets taken to relieve a headache may cause another, but there is overwhelming evidence that a lot of people who take 30 or more tablets a month are likely to wake up each day with a recurrence of their headache. Breaking the vicious circle may be difficult, and sometimes admission to hospital for 'tests' may be needed, but a week off all drugs will often bring dramatic relief. As far as headache is concerned, the worst possible advice is 'keep taking the tablets'.