This study examines the 1 year prevalence rates of headache syndromes in an epidemiologic cohort study of young adults ages 29-30 in Zurich, Switzerland. The 1 year prevalence rates of headache subtypes were 3.3% for migraine with aura and 21.3% of migraine without aura as defined by the International Headache Society (IHS) criteria. The demographic distribution, clinical features, sequelae, and treatment patterns of subjects with specific headache subtypes are described. The rates of migraine are compared to those of other community samples that have employed the IHS criteria for headache subtypes. Subjects with migraine reported pervasive impairment in nearly every life role including occupation, leisure, and social relationships. Despite the substantial degree of impairment in occupational and social functioning that was associated with migraine, an extremely low proportion of subjects had received professional treatment for headache. These results suggest that a concerted effort should be directed towards education regarding the classification of headache and the availability of efficacious treatment for migraine.