Complex Regional Pain Syndrome

(CRPS; Reflex Sympathetic Dystrophy [RSD]; Causalgia; Sympathetically Maintained Pain)


Complex regional pain syndrome (CRPS) is a chronic condition that affects the nerves and blood vessels of 1 or more limbs.

There are 2 types:

  • Type 1—no injury to the nerves can be found, may be referred to as reflex sympathetic dystrophy (most common)
  • Type 2—nerve injury can be found (also described as causalgia)

Complex Regional Pain Syndrome

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CRPS has many causes such as:

How CRPS develops isn't clear. One or more below may play a role:

  • Genes
  • How the immune system works
  • Psychological problems such as anxiety, anger, stress, or depression

Risk Factors

The chances of CRPS is higher for:

  • Having any of the problems listed above
  • Limb immobilization
  • Longer than normal healing time
  • The use of certain medicines


Symptoms mainly appear after an injury. The most common is long term pain. It may be constant or severe. Pain is described as burning, throbbing, aching, squeezing, or shooting.

These may change over time and cause:

  • Sensitivity to touch or even a light breeze
  • Swelling in the arm or leg
  • Sweating patterns that aren’t normal
  • Excessively warm or cool skin
  • Hair and nails that become brittle and crack
  • Movements in the arm or leg such as a tremor, jerking, or spasms
  • A pale, blue, or shiny look to the skin
  • Limited joint movement


You will be asked about your symptoms and health history. Your answers and physical exam may point to CRPS. Testing is done to rule out other conditions. This can be done with:

Imaging tests usually aren't needed unless there is a certain reason to have them.


The goal is to ease pain and help you function better. Early care may help you get better faster. In some cases, problems go away on their own. This is more common in children. One or more methods may be used:

  • Therapy to help with muscle strength, flexibility, and daily activies. These may lower pain and help you move around better.
  • Counseling to help with depression, anxiety, and stress. It may be needed to cope with pain and loss of function.
  • Cognitive behavioral therapy is a form of talk therapy. It focuses on how the way you think affects the way you feel and act.
  • Medicines are used to:
    • Ease pain and swelling
    • Relax your muscles
    • Strengthen your bones
  • Nerve blocks
  • Surgery to destroy certain nerves that are causing problems (may also worsen problems in some cases)
  • Implants—electrical impulses are sent to the spine to control pain


CRPS can't be prevented since the cause is unknown.


International Research Foundation for RSD/CRPS
U.S. Pain Foundation



Complex regional pain syndrome (CRPS). EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated December 1, 2017. Accessed August 23, 2018.
Complex regional pain syndrome (CRPS). Merck Manual Professional Version website. Available at: Updated August 2018. Accessed August 23, 2018.
Complex regional pain syndrome fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: Updated July 6, 2018. Accessed August 23, 2018.
8/10/2007 DynaMed Plus Systematic Literature Surveillance http://www.dynamed... : Zollinger PE, Tuinebreijer WE, Breederveld RS, Kreis RW. Can vitamin C prevent complex regional pain syndrome in patients with wrist fractures? A randomized, controlled, multicenter dose-response study. J Bone Joint Surg Am. 2007;89:1424-1431.
11/9/2009 DynaMed Plus Systematic Literature Surveillance http://www.dynamed... : Cacchio A, DeBlasis, E, Necozione S, di Orio F, Santilla V. Mirror therapy for chronic complex regional pain syndrome type 1 and stroke. N Engl J Med. 2009;361(6):634-636.
4/24/2014 DynaMed Plus Systematic Literature Surveillance http://www.dynamed... : Wise JN, Weissman BN, et al. American College of Radiology (ACR) Appropriateness Criteria for chronic foot pain. Available at: Updated 2013.
Last reviewed May 2018 by EBSCO Medical Review Board Marcin Chwistek, MD
Last Updated: 8/23/2018

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