Migraine syndromes are characterized by headache episodes lasting 4-72 hours, accompanied by other symptoms. The headache is usually unilateral (commonly around the eye or temple), moderate to sever, "pulsating" or "throbbing," and aggravated by activity. Accompanying symptoms and signs must include either nausea and vomiting or photophobia and phonophobia for diagnosis. Subtypes of migraine are based on specific symptom complexes prior to or during the headache, but the general diagnostic and management strategy is common to the group. Migraine is probably due to an inherited predisposition in CNS serotonin receptors (5HT-1), which can be activated by a variety of factors to precipitate an attack.