The patient is often female and complains of one sided throbbing headaches that are preceded by an aura (warning that the headache is coming on). The prodorme consists of progressively increasing (fortification) scotoma (blind spot) surrounded by flashing lights. This lasts for about 30 minutes and is replaced by a disabling headache that lasts for several hours to as long as 1 to 3 days, causing the patient to seek a dark environment. There is often associated nausea and vomiting. There is a family history of similar headaches.
There appears to be a wide variety of triggers for migraines, including variation in sleeping or eating habits, environmental pollutants, certain medications (including vasodilators), and food. With food, the primary triggers include chocolate, caffeine, nitrates, cheese, nuts, wine, and a host of other individualized triggers. There is also a hormonal relationship, as is seen in women. Supplementation with magnesium before menses may prevent some women's menstrual migraines. Although in adults there is a clear female predominance, there is some evidence that under the age of 12, migraine is more common in boys. There is a gradual shift to female predominance such that at age 20 the female-to-male ratio is 2:1 and between 42 and 44 years it is about 3:1.