A migraine is an intense, throbbing headache that may be accompanied by nausea or dizziness. It can last from a few hours to several days. Unfortunately, not much about migraines is understood. Stress, bright lights, and certain smells can trigger migraines. Some medications and a lack of (or too much) sleep can also trigger a migraine headache. Certain foods, such as alcohol, aged cheeses, chocolate, and foods containing aspartame or MSG (monosodium glutamate), can cause a migraine in some people.