According to The National Headache Foundation, some 23 million people in the U.S. suffer from migraines.
Women are more likely than men to have migraines, perhaps because of hormonal cycles.
However, both sexes have them. Although there are many manifestations of migraine, they are all caused by biochemical changes in the brain which lead to changes in the size of arteries in the head. First the blood vessels constrict, then they expand, and that's when the pain begins. About one-third of migraine sufferers experience an aura at the beginning of the attack. This may be seen as flashing lights, wavy lines at the periphery of the visual field, even tunnel vision or a blind spot, any of which can be frightening even though usually of short duration.