CausesBy Mayo Clinic staff
Although much about the cause of migraines isn't understood, genetics and environmental factors appear to play a role.
Migraines may be caused by changes in the brainstem and its interactions with the trigeminal nerve, a major pain pathway.
Imbalances in brain chemicals — including serotonin, which helps regulate pain in your nervous system — also may be involved. Researchers continue to study the role of serotonin in migraines.
Serotonin levels drop during migraine attacks. This may cause your trigeminal system to release substances called neuropeptides, which travel to your brain's outer covering (meninges). The result is headache pain.
Migraine headache triggers
Whatever the exact mechanism of the headaches, a number of things may trigger them. Common migraine triggers include:
Hormonal changes in women. Fluctuations in estrogen seem to trigger headaches in many women with known migraines. Women with a history of migraines often report headaches immediately before or during their periods, when they have a major drop in estrogen.
Others have an increased tendency to develop migraines during pregnancy or menopause.
Hormonal medications, such as oral contraceptives and hormone replacement therapy, also may worsen migraines. Some women, however, may find their migraines occur less often when taking these medications.
- Foods. Aged cheeses, salty foods and processed foods may trigger migraines. Skipping meals or fasting also can trigger attacks.
- Food additives. The sweetener aspartame and the preservative monosodium glutamate, found in many foods, may trigger migraines.
- Drinks. Alcohol, especially wine, and highly caffeinated beverages may trigger migraines.
- Stress. Stress at work or home can cause migraines.
- Sensory stimuli. Bright lights and sun glare can induce migraines, as can loud sounds. Unusual smells — including perfume, paint thinner, secondhand smoke and others — can trigger migraines in some people.
- Changes in wake-sleep pattern. Missing sleep or getting too much sleep may trigger migraines in some people, as can jet lag.
- Physical factors. Intense physical exertion, including sexual activity, may provoke migraines.
- Changes in the environment. A change of weather or barometric pressure can prompt a migraine.
- Medications. Oral contraceptives and vasodilators, such as nitroglycerin, can aggravate migraines.
- NINDS migraine information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/migraine/migraine.htm. Accessed April 4, 2013.
- Headache: Hope through research. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/headache/detail_headache.htm. Accessed April 4, 2013.
- Cutrer FM, et al. Pathophysiology, clinical manifestations and diagnosis of migraine in adults. http://www.uptodate.com/home. Accessed April 4, 2013.
- Daroff RB, et al. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-1-4377-0434-1..C2009-0-40427-6--TOP&isbn=978-1-4377-0434-1&uniqId=364938937-2. Accessed April 4, 2013.
- Bajwa ZH, et al. Acute treatment of migraine in adults. http://www.uptodate.com/home. Accessed April 4, 2013.
- Calhoun AH. Estrogen-associated migraine. http://www.uptodate.com/home. Accessed April 5, 2013.
- Martin KA, et al. Risks and side effects associated with estrogen-progestin contraceptives. http://www.uptodate.com/home. Accessed April 5, 2013.
- Solomon DH. Nonselective NSAIDs: Overview of adverse effects. http://www.uptodate.com/home. Accessed April 8, 2013.
- Bajwa ZH, et al. Preventive treatment of migraine in adults. http://www.uptodate.com/home. Accessed April 4, 2013.
- Neurological diagnostic tests and procedures. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/misc/diagnostic_tests.htm. Accessed April 9, 2013.
- Headaches and complementary health approaches. National Center for Complementary and Alternative Medicine. http://nccam.nih.gov/health/pain/headachefacts.htm?nav=gsa. Accessed April 9, 2013.
- Ramzan M, et al. Headache, migraine and stroke. http://www.uptodate.com/home. Accessed April 9, 2013.
- Cruse RP. Management of migraine headache in children. http://www.uptodate.com/home. Accessed April 10, 2013.
- U.S. News best hospitals 2012-2013. U.S. News & World Report. http://health.usnews.com/best-hospitals/rankings. Accessed April 4, 2013.
- Tintinalli JE, et al. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=40. Accessed April 26, 2013.
- Swanson JW (expert opinion). Mayo Clinic, Rochester, Minn. April 25, 2013.