Foods.
Some migraines appear to be triggered by certain foods. Common offenders include alcohol, especially beer and red wine; aged cheeses; chocolate; aspartame; overuse of caffeine; monosodium glutamate — a key ingredient in some Asian foods; salty foods; and processed foods. Skipping meals or fasting also can trigger migraine attacks.
Stress.
Stress at work or home can instigate migraines.
Sensory stimuli.
Bright lights and sun glare can induce migraines, as can loud sounds. Unusual smells — including pleasant scents, such as perfume, and unpleasant odors, such as paint thinner and secondhand smoke — can also trigger migraines.
Changes in wake-sleep pattern.
Either missing sleep or getting too much sleep may serve as a trigger for migraines in some individuals, as can jet lag.
Changes in the environment.
A change of weather or barometric pressure can prompt a migraine.
Medications.
Certain medications can aggravate migraines, especially oral contraceptives and vasodilators, such as nitroglycerin.