Chicago—When a builder recently arrived at an emergency department, writhing in pain with a 12-inch nail lodged in his foot, nurses carefully removed his boot to find that the nail was harmlessly inserted between two toes. Seeing this, the man's pain suddenly vanished.
At the other end of the spectrum, sometimes people in unusual circumstances are impervious to the pain expected from a genuine injury. For example, individuals injured during an emergency situation may not feel pain until the crisis if over.
Hampton T. A World of Pain: Scientists Explore Factors Controlling Pain Perception. JAMA. 2006;296(20):2425-2427. doi:10.1001/jama.296.20.2425