Persistent pain infrequently complicates injury to bone, soft tissue, and peripheral nerve. Reflex sympathetic dystrophy (RSD) is a generic term used to indicate a clinical syndrome consisting of pain (usually burning in quality), hyperpathia, dystrophic changes in skin, nails, and subcutaneous tissues, and sympathetic dysfunction occurring in response to bone and soft tissue injury. Causalgia is a special type of RSD complicating partial injury to peripheral nerve in which there is intense pain, sympathetic dysfunction, and dystrophic changes in the limb, and often a beneficial response to sympathetic blockade. Current available treatments of neuropathic pain, and the proposed mechanisms of pain, hyperalgesia, and sympathetic dysfunction occurring in the RSDs, will be reviewed. An approach to the management of patients with RSD will be proposed.