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by Wood D

Complex Regional Pain Syndrome

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


Complex regional pain syndrome (CRPS) refers to a chronic condition that affects the nerves and blood vessels of 1 or more limbs.
There are 2 types of CRPS:
  • CRPS 1, previously called reflex sympathetic dystrophy or RSD, has no observable nerve damage.
  • CRPS 2, previously called causalgia, produces similar symptoms after a verified nerve injury has occurred.
Complex Regional Pain Syndrome
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The cause of CRPS is not known. The condition likely results from several factors. It may involve overactivity of the sympathetic nervous system. Inflammation may also play a role in the disorder.

Risk Factors

Factors that may increase your risk of CRPS include:
  • Trauma
  • Fractures
  • Limb immobilization
  • Longer than normal healing time
  • The use of certain medications such as ACE inhibitors


Symptoms usually appear after an injury. The most important symptom of CPRS is prolonged pain that may be constant or severe. Pain is typically described as burning, throbbing, aching, squeezing, or shooting.
Symptoms of CRPS change over time and may include:
  • Sensitivity to touch or even a light breeze
  • Swelling in the arm or leg
  • Unusual sweating patterns
  • Excessively warm or cool skin
  • Hair and nails that become brittle and crack
  • Abnormal movement in the arm or leg, such as a tremor, jerking, or spasms
  • A pale, blue, and/or shiny look to the skin
  • Limited joint movement


You will be asked about your symptoms and medical history. A physical exam will be done. You may be referred to a pain specialist.
Images may be taken of your bodily structures. This can be done with:
The electrical activity in your nerves and muscles may need to be tested. This can be done with:
You may need to have your body's heat measured. This can be done with a thermogram.
You may need to have your autonomic nervous system evaluated. This can be done with quantitative sudomotor axon reflex test (QSART), resting sweat output (RSO), or the resting skin temperature (RST).


Treatment aims to relieve pain and improve function. Early therapy may lead to better outcomes. In some cases, the condition goes away on its own; this is more common in children. Talk with your doctor about the best treatment plan for you. Options include:

Physical and Occupational Therapy

Physical and occupational therapy may help reduce pain and increase mobility.


Long-term pain often leads to depression or anxiety . Counseling is often required to help patients deal with chronic pain and loss of function.
Cognitive behavioral therapy may help you manage pain. It is a form of talk therapy that focuses on how the way you think affects the way you feel and act.


Your doctor may advise the following medications:
  • Pain relievers
  • Topical pain relievers that are applied to the skin
  • Bisphosphonates
  • Antiseizure medications
  • Corticosteroids


A surgical procedure called sympathectomy can permanently destroy sympathetic nerves. In some cases however, surgery may worsen symptoms.

Other Treatments

A device may be implanted in your spine. It will deliver electric stimulus to your spinal cord to manage pain.


There are no known ways to prevent CRPS.


International Research Foundation for RSD/CRPS
Reflex Sympathetic Dystrophy Syndrome Association


Health Canada
RSD Canada


Complex regional pain syndrome. EBSCO DynaMed website. Available at: Updated November 19, 2014. Accessed June 4, 2015.
Complex regional pain syndrome fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: Updated February 23, 2015. Accessed June 4, 2015.

Harden RN, Bruehl SP. Diagnosis of complex regional pain syndrome: signs, symptoms, and new empirically derived diagnostic criteria. Clinical Journal of Pain. 2006;22:415-419.
8/10/2007 DynaMed's Systematic Literature Surveillance 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's Systematic Literature Surveillance 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's Systematic Literature Surveillance Wise JN, Weissman BN, et al. American College of Radiology (ACR) Appropriateness Criteria for chronic foot pain. Available at: Updated 2013. Accessed June 4, 2015.

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