The effect of past-injury on pain threshold and tolerance

Forty male veterans who had been injured during their military service in the Israeli Defense Forces were assessed for pain threshold and tolerance in a thermal pain procedure. Based on their medical records, subjects were classified by three independent judges as having been either severely or lightly injured. Veterans who had been severely injured had much higher threshold and tolerance for thermal pain as compared to lightly injured veterans. These results are interpreted as supporting adaptation-level theory, which implies that painful experiences can change the internal anchor points for the subjective evaluation of pain.