What causes Complex regional pain syndrome ?
What causes complex regional pain syndrome? The underlying cause of complex regional pain syndrome (CRPS) is not well understood. In most cases it occurs after an illness or injury that did not directly damage the nerves in the affected area (Type I). In some cases, it occurs after a specific nerve injury (Type II). The exact trigger of CRPS after an injury is not known, but it may be due to abnormal interactions between the central and peripheral nervous systems, and/or inappropriate inflammatory responses.