RSD is a symptom complex, representing an exaggerated response to injury or tissue damage. The amplification of the normal responses probably occurs both in the periphery and in the central nervous system. Diagnostic criteria are still under discussion, and treatment modalities are still directed toward the symptoms because the pathophysiology is not known. The pain of the condition may be sympathetically maintained of sympathetically independent (or both), and sympathetic blockade is useful in the former category. Treatment modalities must be directed toward optimizing both comfort and function of the affected extremity. Such treatment programs might occur in a multidisciplinary setting.