What is complex regional pain syndrome?

Complex regional pain syndrome (CRPS) is a chronic pain condition that is believed to be the result of dysfunction in the central or peripheral nervous systems. Typical features include dramatic changes in the color and temperature of the skin over the affected limb or body part, accompanied by intense burning pain, skin sensitivity, sweating, and swelling. CRPS I is frequently triggered by tissue injury; the term describes all patients with the above symptoms but with no underlying nerve injury. Patients with CRPS II experience the same symptoms but their cases are clearly associated with a nerve injury.

Older terms used to describe CRPS are "reflex sympathetic dystrophy syndrome" and "causalgia," a term first used during the Civil War to describe the intense, hot pain felt by some veterans long after their wounds had healed.

CRPS can strike at any age and affects both men and women, although most experts agree that it is more common in young women.