Pain must be the bane of many a doctor's existence. It's a major symptom and indicator of many illnesses, but doctors have to rely on humans to describe and rate it, and humans are a distinctly unreliable source of information. What's a "7" on the pain scale for someone might be a "4" for another. What's a "pulsing" pain for someone might be a "pounding" for someone else. At Stanford, some doctors are figuring out the first steps to objectively measure pain, finally putting that all to rest.