In a cross-sectional epidemiological study of headache disorders information on precipitating factors, age at onset, influence of menstruation and pregnancy and use of oral contraceptives was collected. The presence of migraine and tension-type headache was ascertained by a clinical interview and examination using the operational diagnostic criteria of the International Headache Society. The prevalence of migraine and tension-type headache was also analysed in relation to variables of lifestyle: physical activity, smoking, consumption of coffee, alcohol intake and sleep pattern. In both migraine and tension-type headache, the most conspicuous precipitating factor was stress and mental tension. Other common precipitants were alcohol, weather changes and menstruation. Disappearance or substantial improvement of the headache during pregnancy was more frequent in migraineurs than in tension-type headache sufferers. The age at onset of both migraine and tension-type headache differs between men and women. Female hormones may be an important factor responsible for the sex difference of headache disorders. The level of physical activity showed no association with migraine, but a significantly higher prevalence of tension-type headache in men with exclusively sedentary activity emerged. Smoking, coffee and alcohol consumption showed no significant associations with the headache disorders. Sleep pattern was significantly associated with migraine and tension-type headache in both univariate and multivariate analyses. In conclusion, migraine and tension-type headache seem to be different with regard to a number of endogenous and exogenous factors.