The exact causes of migraine are unknown. Doctors think that migraine may start with an underlying central nervous system disorder. When triggered by various stimuli, this disorder may set off a chain of neurologic and biochemical events, some of which subsequently affect the brain's blood vessel (vascular) system.
There is certainly a strong genetic component to migraine. Several different genes are likely to be involved in the great majority of migraine cases.
Numerous other brain chemicals and nerve pathway disrupters may play a role. They include the neurotransmitter (brain chemical messenger) serotonin, magnesium deficiencies, and abnormalities in the channels within cells that transport electrical ions such as calcium.
A wide range of events and conditions can alter conditions in the brain that bring on nerve excitation and trigger migraines. They include:
- Emotional stress
- Physical exertion (such as intense exercise, lifting, or even bowel movements or sexual activity)
- Abrupt weather changes
- Bright or flickering lights
- High altitude
- Travel motion
- Lack of sleep
- Skipping meals
- Certain types of foods, and chemicals contained in them. More than 100 foods and beverages may potentially trigger migraine headache. Caffeine is one such trigger. Caffeine withdrawal can also trigger migraines in people who are accustomed to caffeine. Red wine and beer are also common triggers. Preservatives and additives (such as nitrates, nitrites, and MSG) can also trigger attacks. Doctors recommend that patients keep a headache diary to track which foods trigger migraine.
- Fluctuations of female hormones may trigger migraine in women
Review Date: 11/04/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.