Complex Regional Pain Syndrome

Complex regional pain syndrome is a form of chronic pain that typically affects your arm or leg. It can occur after an injury or surgery, with or without nerve damage.

Overview and Symptoms

Overview and Symptoms

p>Complex regional pain syndrome (CRPS) is uncommon, and the cause is not well understood. It may be due to injured nerves and can be related to other conditions, such as shingles, stroke, heart disease or cancer.

CRPS was previously called reflex sympathetic disorder (RSD), so you may sometimes hear it referred to as that. There are two types of CRPS:

  • Type I: no previous nerve damage
  • Type II: known prior nerve damage or abnormality

Common symptoms include:

  • Intense pain that can be described as burning and/or throbbing
  • Swelling
  • Changes in skin color; shiny over area of pain
  • Changes in hair and nail growth
  • Change in temperature
  • Increased sweating


A physician may diagnose a patient with CRPS based on their symptoms and physical examination. Imaging and nerve function tests may also be ordered. A sympathetic nerve block can also help diagnose CRPS.

While some people may improve on their own, early diagnosis and treatment will be helpful in relieving pain. Physical therapy and maintaining movement in the affected part of the body is very important. Medications, such as non-steroidal anti-inflammatory drugs, as well as other medications to treat pain, may be prescribed. Severe pain that does not respond to other treatment options may improve with stimulating the spinal cord with an implantable device.