Sunlight & Migraines

Migraines are chronic severe headaches often accompanied by nausea. In her June 2009 review of environmental causes of migraines published in "Headache Currents," Dr. Deborah Friedman reported that sunlight can trigger migraines, and migraine sufferers are sensitive to bright light.

Migraines and Sunlight

• Dr. Deborah Friedman reported that sunlight, glare or other bright light can trigger a migraine in about 30 percent of migraine sufferers. Heat and humidity, which often accompany bright sunlight, can also trigger migraines.

Light Sensitivity

• According to Dr. Friedman, migraine sufferers are hypersensitive to light. When exposed to progressively brighter lights, migraine sufferers feel discomfort at lower levels of light than other people.

Light and Pain

• Dr. Friedman's review showed that migraine sufferers have lower pain thresholds after looking at bright light, while other people have higher pain thresholds following exposure to bright light. This suggests that sunlight can worsen the pain.

Vision and Migraine

• Before a migraine, you might experience blind spots or flashes of light. Sunlight can trigger migraines, and migraine sufferers crave a dark, quiet room during an episode. It is not clear exactly how the visual nerves interact with the trigeminal nerve, the major pain pathway at the root of migraines.

Serotonin

• Levels of the nerve chemical serotonin drop during migraines, triggering the trigeminal nerve. Control of serotonin levels might be the link between sunlight and migraines, because sunlight can influence the number of serotonin receptors.