When to worry about headache. Head pain as a clue to intracranial disease.

Careful evaluation of headache is important to detect potentially morbid but treatable causes. Although such causes represent only 10% of all emergency department visits for headache, the consequences of a missed diagnosis can be severe. Unfortunately, the cost of performing computed tomography or magnetic resonance imaging for every patient with headache is prohibitive. However, familiarity with the differential diagnostic considerations, together with a high index of suspicion, should allow physicians to perform efficient, cost-effective examinations of all patients who seek treatment for headache.