Migraine is a type of recurring headache. It involves nerves and brain chemicals. Other sensations (eg, auras) may come before a migraine headache.

There are two types of migraines:

  • Occurring with an aura (formerly called "classic")
  • Occurring without an aura (formerly called "common")

Migraine may happen several times a week or once every couple of years. They can be so severe that they interfere with the ability to work and carry on normal activities.

While the precise cause is not known, many potential triggers have been identified. Common triggers include:

  • Environmental triggers (eg, odors, bright lights)
  • Dietary triggers (eg, alcohol)
  • Certain medications
  • Changes in sleep patterns
  • Stress
  • Physiologic changes (eg, menstruation, puberty)
  • Weather changes

A trigger sets the process in motion. It is possible that the nervous system reacts to the trigger by conducting electrical activity. This spreads across the brain. It leads to the release of brain chemicals, which help regulate pain.