What Are Migraine Headaches, and Why Do They Happen?

What Are Migraine Headaches?

Migraine headaches are headaches that cause severe, throbbing pain, often along with nauseavomiting, and sensitivity to light or sound. They generally last between 4 and 72 hours. Many people feel symptoms before their migraine starts that signal that one is coming on. Those are called an aura and usually last under an hour.

Symptoms of an aura include:

  • Changes in your vision (even brief blindness)
  • Visual blind spots in your visual field
  • Flashes of light or odd patterns before your eyes
  • Double vision
  • Dizziness
  • The feeling that the room is spinning around you
  • Trouble with balance and walking
  • More sensitivity to smells
  • A numb or tingly feeling in your face, neck, head, or arms

Most people start having migraine headaches between ages 10 and 40. They’re three times more common for women. However, many women find that their migraines improve or disappear after age 50.

What Causes Migraine Headaches?

People who get migraines have brain cells that seem to be too sensitive to some triggers. Things that don’t cause such headaches in most people -- such as intense emotion, exercising hard, foods, smells, or sounds -- set off events in the brains of people with migraines. That makes blood vessels get narrow and then widen. Then the brain releases chemicals that cause inflammation and pain.

Migraines tend to run in families. In fact, more than 50% of people who get them have family members who do, too.

Migraine triggers can include:

  • Stress
  • Hunger (low blood sugar)
  • Poor sleep
  • Alcohol, especially red wine
  • Aged cheeses
  • Meats that have nitrates or nitrites, usually deli-type meats such as pepperoni, salami, sausages, lunch meats, and hot dogs
  • Foods that have monosodium glutamate (MSG), which comes in certain seasonings, baking mixes, bouillon, stuffing mixes, Chinese food, frozen foods, processed meats, prepared soups, and condiments
  • Many different types of medications, especially birth control pills or estrogen replacement therapy

Women tend to get migraine symptoms right before their periods, which makes researchers think that a lack of estrogen may cause these headaches. Migraine headaches often get less severe during the last 2 trimesters of pregnancy, perhaps because the estrogen level goes up. Some women, however, still have problems with headaches throughout their pregnancy.

WebMD Medical Reference Reviewed by Lawrence C. Newman, MD on August 18, 2017



Young, W. Migraines and Other Headaches, Demos Medical publishing, 2004. 

Blumenfeld, A. Dermatology Clinic, April 2004. 

Sheftell F. Journal of the American Academy of Nurse Practitioners, August 2005.

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