Information About Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a chronic condition with no clearly understood cause. Generally, CRPS affects the arms or legs, and in some cases, affects other parts of the body. CRPS generally affects women more than men. While CRPS can occur at any age, it is most common in people between the ages of 40 and 60.


There are two types of CRPS. While the symptoms are similar in the two types, they have different causes:

  • Type I: occurs after an illness or injury that didn't cause nerve damage in the affected limb. A majority of people – nearly 90 percent – with CRPS have type I.
  • Type II: follows a distinct nerve injury.

Various types of trauma – major or minor – can cause complex regional pain syndrome, including:

  • Gunshot wound
  • Shrapnel blast
  • Surgery
  • Heart attacks
  • Infections
  • Fractures
  • Sprains


In many patients, complex regional pain syndrome causes intense, burning pain. Additional signs and symptoms include:

  • Aching pain
  • Swelling in the joints
  • Discolored skin
  • Abnormal temperature
  • Abnormal sweating
  • Extreme skin sensitivity
  • Changes in nail and hair growth
  • Muscle spasms or weakness
  • Muscle loss
  • Decreased mobility


A variety of tools can be used to diagnose complex regional pain syndrome, including:


When treatment for CRPS is started early – within a few months after symptoms begin – patients are more likely to see improvements or remission of CRPS. Treatments can include:

  • Medications
  • Applying heat and cold
  • Capsaicin cream
  • Physical therapy
  • Sympathetic nerve-blocking medication
  • Transcutaneous electrical nerve stimulation (TENS)
  • Biofeedback
  • Spinal cord stimulation