http://emedicine.medscape.com/article/821863-overview emedicine.medscape.com Medscape Migraine Headaches 3,328 in the U.S. in 2011 Medscape caffeine toxicity Caffeine Toxicity http://emedicine.medscape.com/article/821863-overview caffeine toxicity Caffeine Medscape Emedicine Medscape Reference: Caffeine Toxicity