Complex Regional Pain Syndrome (CRPS) is a chronic (lasting greater than six months) pain condition that most often affects one or both limbs (arm, leg, hand, or foot) usually after an injury. CRPS is characterized by prolonged or excessive pain and changes in skin color, temperature, and/or swelling in the affected area. CRPS symptoms vary in severity and duration, although some cases are mild and eventually go away. In more severe cases, individuals may not recover and may have long-term disability. Over time, the affected limb can become cold and pale. It may undergo skin and nail changes as well as muscle spasms and tightening.
CRPS occasionally may spread from its source to elsewhere in your body, such as the opposite limb. In some people, signs and symptoms of CRPS go away on their own. In others, signs and symptoms may persist for months to years. Treatment is likely to be most effective when started early in the course of the illness.