Pain and fatigue, subjectively experienced, are two of the commonest complaints made by patients suffering from a variety of psychoneurotic and psychotic disorders. Neither phenomenon has so far been adequately studied with the available objective techniques, and the present paper embodies results of preliminary experimental investigations of fatigue and pain tolerance, together with a review of some of the clinical aspects of the problem.

In psychiatric disorders pain rarely produces overt signs which allow the observer to judge its severity, and the excruciating pain complained of by some patients appears to be accompanied by much less emotional reaction than, for example, the pain experienced by the normal individual after a burn, a crushed finger, or an abdominal catastrophe.