Complex regional pain syndrome (CRPS) is a condition that can occur after an injury or surgery. Ongoing pain in the area of the injury or surgery is the main symptom of CRPS. The pain is much worse and lasts longer than a person would expect for the type of injury they had. Some people don't have an injury or surgery before the pain starts, but most people do. Another name for CRPS is reflex sympathetic dystrophy.

Skin sensitivity, excessive sweating, numbness, and tingling may also occur with CRPS. This condition is not understood well. And it is difficult to diagnose and treat.