Whatever the exact mechanism of the headaches, a number of things may trigger them including:
- 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 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.
Hormonal changes in women such as fluctuations in estrogen seem to trigger headaches for those with known migraines. Others have an increased tendency to develop migraines during pregnancy or menopause. Hormonal medications, such as oral contraceptives and hormone replacement therapy, may also worsen migraines. Some women, however, may find their migraines occur less often when taking these medications.