Complex regional pain syndrome (CRPS) is an uncommon nerve disorder. It causes intense pain, usually in the arms, hands, legs or feet. It happens after an injury, either to a nerve or to tissue in the affected area. Rest and time may only make it worse. The cause of CRPS is unknown, and there is no cure. It can get worse over time, and may spread to other parts of the body. Occasionally it goes away, either temporarily or for good.
