The cause of the migraine is thought to begin with arteries in the brain which spasm, precipitated by stress, hormonal fluctuations, certain medications, foods containing tyramine or phenylalanine (e.g., cheese, chocolate), fatigue, and alcohol.

The result is reduction in blood flow in that artery, followed by blood vessel dilation over-filling of those vessels, causing the severe throbbing or "pounding" headache.