Migraine is a neurological syndrome that can cause a wide range of symptoms during an attack. The most commonly thought of symptom is headache.
Usually, migraines cause episodes of severe or moderate headache (which is often one-sided and pulsating) lasting from four to 72 hours, accompanied by gastrointestinal upsets, such as nausea and vomiting, and a heightened sensitivity to bright lights (photophobia) and noise (hyperacusis). Approximately one third of people who experience migraine get a preceding aura, in which a patient senses a strange light or unpleasant smell.
The word migraine is French in origin and comes from the Greek hemicrania, as does the Old English term megrim. Literally, hemicrania means "half (the) head".