Pain has a purpose - it can stop you from touching a flame or from walking on a broken leg. As an injury heals, the pain goes away. Usually. But worldwide, one out of every five people suffers from pain that lasts for months and years, leading to lost jobs, depression, and rising despair when medical interventions fail or health experts hint that a pain sufferer is making it up. From Boulder, Colorado, Shelley Schlender reports that new methods for mapping pain in the brain are providing validation for chronic pain and might someday guide better treatment.