APA Dictionary of Psychology

a headache that is recurrent, usually severe, usually limited to one side of the head, and likely to be accompanied by nausea, vomiting, and photophobia. Migraine headaches may be preceded by an aura of flickering or flashing light, blacking out of part of the visual field, or illusions of colors or patterns. They are much more common in women than in men. Also called sick headache.