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About Complex Regional Pain Syndrome (CRPS)

Chronic Pain


Complex regional pain syndrome is a chronic pain condition that most often affects the arms, legs, hands, or feet. Complex regional pain syndrome is also known as reflex sympathetic dystrophy or causalgia.


Complex regional pain syndrome usually develops in a limb after an injury (such as a broken bone) or surgery. The exact cause of CRPS is unknown.


The overriding symptom is extreme pain, frequently described as burning. Other symptoms can include:

  • Sensitivity to touch
  • Skin changes
  • Swelling
  • Weakness
  • Decreased function of the hand/foot


Your doctor may base a diagnosis of complex regional pain syndrome on:

  • Medical history
  • Physical examination
  • Bone scan
  • Nervous system tests
  • X-rays
  • Magnetic resonance imaging (MRI)

Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.