Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. It may happen after an injury, either to a nerve or to tissue in the affected area. Rest and time may only make it worse.

Symptoms in the affected area are

• Dramatic changes in skin temperature, color, or texture
• Intense burning pain
• Extreme skin sensitivity
• Swelling and stiffness in affected joints
• Decreased ability to move the affected body part

The cause of CRPS is unknown. There is no specific diagnostic test. Your doctor will diagnose CRPS based on your signs and symptoms.

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. Treatment focuses on relieving the pain, and can include medicines, physical therapy, and nerve blocks.

NIH: National Institute of Neurological Disorders and Stroke