Stress accounts for 80 % of all migraines, according to a study in the journal Cephalalgia. That's because it causes fluctuations in cortisol and adrenaline - the fight-or-flight hormones - which can lead to pain and nausea, says Sheena K. Aurora, MD, medical director of the Headache Center at Swedish Medical Center in Seattle. Stress can also make you clench your jaw and neck muscles, causing neck pain that, in turn, can set off tension headaches.
By Winnie Yu Scherer