Assessment and management of disability in chronic daily headache.

The problem of chronic daily headache is ubiquitous and affects up to 5% of the world's population. In most cases, it is associated with the overuse of symptomatic medications in patients with a history of migraine or tension-type headaches, indicating an urgent need for intensive public and professional education. In a minority, it develops de novo from episodic migraine without excessive drug intake. The condition is likely to have a biologic (rather than psychologic) basis. The degree with which it negatively impacts patients and their family is reviewed. Current treatment regimes are described, but it is noted that those currently employed are seldom adequate in the long term, possibly because of the unavailability of nonpharmacologic treatments to most people or because of the low frequency of use of preventative pharmacologic and lifestyle measures.