The Ascent of Vapors
Any plausible explanation of migraine needs to account for a wide and varied set of symptoms. The frequency, duration, experience and catalysts of episodes differ greatly. Victims have, on average, one or two daylong attacks every month. But 10 percent get them weekly, 20 percent experience them for two to three days, and up to 14 percent have them more than 15 days a month. Often the pain strikes just one side of the head, but not always. Migraines in people prone to them can be set in motion by such a variety of events that they seem inescapable; alcohol, dehydration, physical exertion, menstruation, emotional stress, weather changes, seasonal changes, allergies, sleep deprivation, hunger, altitude and fluorescent lights are all cited as triggers. Migraines occur in all ages and both genders, yet women between the ages of 15 and 55 are disproportionately hit—two thirds of cases occur in this population.
Physicians over the years have proposed many reasons for why these headaches arise. Galen in ancient Greece attributed them to the ascent of vapors, or humors, from the liver to the head. Galen’s description of hemicrania—a painful disorder affecting approximately one half of the head—is indeed what we refer to as migraine today: the old word “hemicrania” eventually became “megrim” and ultimately “migraine.”


