Epidemiology of headache.

Epidemiological studies conducted in the general population point to average headache prevalence rates of 46% for 1-year prevalence and of 64% for lifetime prevalence. For migraine, most studies conducted in the adult general population of western Europe and North America indicate rates between 5% and 9% in men, and between 12% and 25% in women. Non-western countries report lower figures. Migraine shows no gender differences in children, while in the elderly its frequency appears much reduced in both genders. About one-third of migraineurs suffer from migraine with aura. For tension-type headache, prevalence data reports in the literature are few and conflicting: rates range from 11% in Singapore to 20-40% in the USA and over 80% in Denmark. It is worth noting that the highest figures are found in studies where a personal interview has been employed. This probably indicates that the prevalence of this headache subtype is particularly sensitive to the method of data collection. Cluster headache occurs in 1-3 per thousand of the general population, with a gender (M:F) ratio of about 3:1. About 4% of the adult general population suffers from chronic daily headache.