Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea. It is about three times more common in women than in men.
The typical migraine headache is unilateral (affecting one half of the head) and pulsating in nature and lasting from four to 72 hours; symptoms include nausea, vomiting, photophobia (increased sensitivity to light) and phonophobia (increased sensitivity to sound); the symptoms are generally aggravated by routine activity.
The cause of migraine headache is unknown; the most supported theory is that it is related to hyperexcitability of the cerebral cortex and/or abnormal control of pain neurons in the trigeminal nucleus of the brainstem.