THERE IT HURTS, scribbled the German artist Albrecht Dürer five centuries ago on a postcard-size self-portrait he sent to a physician about his mysterious illness. Dürer’s symptoms included fever, nausea and pain, the site of which he marked with a yellow oval. Though it’s not known whether the drawing was of help, or even what the doctor’s diagnosis was (later theories ranged from malaria to tuberculosis to poisoning), Dürer’s practical masterpiece is the first known instance of a pain map. Simple outlines of the body on which patients pinpoint where it hurts, pain maps can help clarify, for instance, whether pelvic pain originates from internal organs or a musculoskeletal source. Most pain maps, like Dürer’s, involve pen and paper; however, researchers are developing 3-D computer versions to track pain more accurately, aiming to create software for chronic pain patients to chart the location and quality of their pain throughout the day.