Migraine.

Migraine affects about 1 billion people worldwide, and up to 15% of adults in the United States have migraine attacks in any given year. Migraine is associated with substantial adverse socioeconomic and personal effects. It is the second leading cause of years lived with disability worldwide for all ages and the leading cause in women aged 15 to 49 years. Diagnostic uncertainty increases the likelihood of unnecessary investigations and suboptimal management. This article advises clinicians about diagnosing migraine, ruling out secondary headache disorders, developing acute and preventive treatment plans, and deciding when to refer the patient to a specialist.