Headache is a common problem. There are nearly 14,000 visits each year to ambulatory care settings for headache; half of these are to a primary care physician. One out of four households has at least one member who suffers from migraine headache, and migraine headaches cost American employers $13 billion a year. Tension headaches are more prevalent; 95% of women and 90% of men experience at least one tension headache in their lifetime. Headaches are classified commonly as primary or secondary. This article examines the diagnosis and treatment of the three most common types of headaches that are seen in primary care practices: migraine, tension, and chronic daily headaches.