APA Dictionary of Psychology

a chronic pain disorder characterized by severe, burning pain, swelling, and autonomic and motor disturbances in a limb following injury or surgery. The diagnostic term reflex sympathetic dystrophy has been largely replaced by complex regional pain syndrome (CRPS) type I, reflecting modern diagnostic criteria that classify CRPS into type I (without confirmed nerve injury, historically reflex sympathetic dystrophy) and type II (with documented nerve injury, formerly known as causalgia).