What causes migraines?

The exact cause of migraine is not fully understood. Most researchers think that migraine is due to abnormal changes in levels of substances that are naturally produced in the brain. When the levels of these substances increase, they can cause inflammation. This inflammation then causes blood vessels in the brain to swell and press on nearby nerves, causing pain.

Genes also have been linked to migraine. People who get migraines may have abnormal genes that control the functions of certain brain cells.

Experts do know that people with migraines react to a variety of factors and events, called triggers. These triggers can vary from person to person and don't always lead to migraine. A combination of triggers—not a single thing or event—is more likely to set off an attack. A person's response to triggers also can vary from migraine to migraine. Many women with migraine tend to have attacks triggered by:

    * lack of or too much sleep
    * skipped meals
    * bright lights, loud noises, or strong odors
    * hormone changes during the menstrual cycle
    * stress and anxiety, or relaxation after stress
    * weather changes
    * alcohol (often red wine)
    * caffeine (too much or withdrawal)
    * foods that contain nitrates, such as hot dogs and lunch meats
    * foods that contain MSG (monosodium glutamate), a flavor enhancer found in fast foods, broths, seasonings, and spices
    * foods that contain tyramine, such as aged cheeses, soy products, fava beans, hard sausages, smoked fish, and Chianti wine
    * aspartame (NutraSweet® and Equal®)

To pinpoint your migraine triggers, keep a headache diary. Each day you have a migraine headache, put that in your diary. Also write down:

    * the time of day your headache started
    * where you were and what you were doing when the migraine started
    * what you ate or drank 24 hours before the attack
    * each day you have your period, not just the first day  (This can allow you and your doctor to see if your headaches occur at the same or similar time as your period.)