Migraine is a severe headache accompanied by sensitivity to light, sound and smells. Women suffer from migraines more than men. Migraines are caused by genetic and environmental factors that trigger changes in the brain and cause swelling of blood vessels. Common triggers include stress, lack of sleep, certain foods and changes in routine. Migraines can be debilitating and last up to three days, causing nausea, vomiting and visual disturbances for some sufferers.