Chronic daily headache

Abstract

Patients with chronic daily headache (CDH) are frequently encountered in headache clinics. By definition, CDH refers to headache frequency of >15 days per month with duration of >4 hours per day (if untreated), and is classified as chronic migraine, chronic tension-type headache, new daily persistent headache and hemicrania continua. Patients with CDH are frequently comorbid with psychiatric disorders and medication overuse, leading to therapeutic hindrance. This article reviews the recent advances in epidemiology, pathophysiology, treatment and prognosis of CDH, including the authors' data done in Taiwan.