Despite extensive description of headache among patients in specialty clinics and general practices in the United States, there have been few community-wide investigations. In a population-based telephone interview study of 10,169 Washington County, Maryland, residents who were 12 through 29 years old, 57.1% of males and 76.5% of females reported that their most recent headache occurred within the previous 4 weeks. Four or more headaches in the preceding month were reported by 6.1% of males and 14.0% of females. The average duration of the subjects' most recent headache was 5.9 hours for males and 8.2 hours for females; 7.9% and 13.9%, respectively, missed part of a day or more of school or work because of that headache. Within the month before interview, 3.0% of males and 7.4% of females had suffered from a migraine headache. Consultations with a physician, by specialty, for headache-related problems are described by sex and age of subjects, as is the use of specific prescription and nonprescription medications.