Headaches and hormones: What's the connection?
http://www.mayoclinic.com/health/headaches/HE000035/30/2008
"Being female has some real health advantages, but not when it comes to headaches — particularly migraines. Fortunately, there's help. In a given year, 18 out of 100 women age 12 and older experience at least one migraine headache, a misfortune that strikes only 6 pecent to 7 percent of men. What's behind the difference? The answer, in a word, is hormones, but the explanation is far from complete."
