Migraines are severe headaches which may last from several hours to several days. They are associated with a narrowing, followed by a swelling, of the blood vessels in the head. Typically, a migraine attack is preceded by warning signs which may include visual disturbances, such as flashing lights, wavy lines, or areas of darkness. A person may become dizzy or experience weakness or numbness in the arms or legs. These sensations may last for an hour or two and usually fade as the headache begins. The pain of a migraine may appear as a throbbing or pounding in the forehead, temple, ear, or eye, and is usually more severe on one side of the head. Other symptoms include nausea, vomiting, or chills. Migraines are sometimes triggered by certain foods, alcohol, oral contraceptives, or stress. Susceptibility to migraines tends to run in families, which has led to the belief that there is an inherited, or genetic, aspect to these headaches. They affect people of all ages and are more common in women. Treatment varies depending on individual health and circumstances. For more information about migraines, contact a health care provider.