Headache is one of the chief complaints among patients visiting primary care physicians. Diagnosis begins with exclusion of secondary causes for headache. More than 90% of patients will have a primary-type headache, so diagnosis can often be completed without further testing. Although tension-type headaches are the most common kind of headache, patients with this type of headache rarely seek treatment unless occurrence is daily. Migraine, which affects more than 30 million people in the United States, is the most common headache diagnosis for which patients seek treatment. Migraine is a chronic, often inherited condition involving brain hypersensitivity and a lowered threshold for trigeminal-vascular activation. Intermittent debilitating attacks are characterized by autonomic, gastrointestinal, and neurologic symptoms. Migraine results in a marked decrease in a patient's quality of life, as measured by physical, mental, and social health-related instruments. Accurate assessment of a patient's disability will guide physicians in prescribing appropriate modes of therapy. However, migraine remains underdiagnosed, and patients with migraine remain undertreated. A comprehensive treatment approach to migraine may include nonpharmacologic measures, as well as abortive and prophylactic medications. Informing patients about realistic treatment expectations, possible delayed efficacy of medications, and avoidance of caffeine and overuse of medications is critical for successful outcomes. Management of migraine is a dynamic process, because headaches evolve over time and medication tachyphylaxis may occur, necessitating changes in therapy. Pathologic findings in the neck constitute an accepted etiology or precipitant for headache. Osteopathic manipulative treatment may reduce pain input into the trigeminal nucleus caudalis, favorably altering neuromuscular-autonomic regulatory mechanisms to reduce discomfort from headache.