Complex Regional Pain Syndrome (CRPS)

Complex regional pain syndrome (CRPS) is a chronic, progressive illness. The main symptoms are severe pain, swelling, and changes in the skin. Although CRPS can occur anywhere in the body, it usually affects an arm, leg, hand, or foot.

CRPS most often follows major trauma, such as a fracture or amputation, but it can even occur after minor trauma, like a sprained ankle. It can also be triggered by surgery, a heart attack or stroke, and infection. In rare cases, CRPS appears spontaneously, without apparent cause. It is more likely to occur during times of increased emotional stress.

The degree of pain is severe and is usually much greater than the injury would normally cause.

CRPS is divided into two groups:

  • Type 1, also called reflex sympathetic dystrophy, which develops without nerve damage.
  • Type 2, which is the result of specific nerve damage.


No one knows the exact cause of CRPS. It may be a disorder of the immune system that affects nervous system, producing inflammation of the nerves that control blood flow, sensation, and temperature.


CRPS typically follows 3 stages of development:

Stage 1

This stage usually lasts 1­–3 months and includes the following symptoms:

  • Severe burning or aching pain that increases with even a very slight touch or breeze.
  • Fluctuations in skin temperature between hot and cold.
  • Rapid growth of hair and nails.
  • Muscle spasms and joint pain.
  • Changes in the skin’s color, appearance, and texture. The skin can become pale, red, purple, or mottled, and appears thin and shiny.
  • Increased sweating.

Stage 2

Stage 2 typically lasts between 3–6 months, during which time the symptoms progress. The skin continues to change and the nails become brittle and cracked. The level of pain increases, and hair growth slows down. The joints stiffen and the muscles weaken.

Stage 3

If CRPS is allowed to progress untreated to this point, it becomes difficult or too painful to move the affected limb. This causes the muscles and tendons to waste (atrophy) and contract, which can ultimately cause clawing of the affected hand or foot. These changes can become permanent.

Symptoms can disappear spontaneously, or they can persist for months or years.


There are no specific tests to diagnose CRPS. Diagnosis is usually made during a physical examination based on symptoms. Certain tests can help provide clues, including a bone scan to detect any changes; and tests that measure differences in skin temperature, blood flow, and sweating between affected and unaffected limbs. In late stages, x-rays can show mineral loss in the bones. Magnetic resonance imaging can also be used to determine if there are tissue changes typical of CRPS.


CRPS has no cure. Treatment is most effective when started early and focuses on relieving symptoms, slowing the progression of the disease, and helping sufferers cope with the pain and lead as normal lives as possible. A team approach provides the best results.

The available noninvasive treatments include:

  • Medication. Several different types of drugs may be prescribed to target the various symptoms of CRPS. They include prescription and non-prescription pain medication; steroids for inflammation; blood pressure medications; drugs that can help prevent or slow bone loss; and antidepressants.
  • Physical and occupational therapy.  It is important to exercise and move the affected limb to maintain flexibility and prevent loss of muscle tissue.
  • Counseling and talk therapy. Psychological support helps combat the depression and anxiety that are common with CRPS.

Several invasive and surgical treatments are also available. These include:

  • Anesthetics injected into the affected limb to numb the pain.
  • A drug pump implanted under the skin to deliver pain medication directly to the spinal cord.
  • spinal cord stimulator, which masks the pain by delivering a tingling or pleasant sensation to the affected site.
  • Surgery to cut the affected nerves and prevent painful impulses from reaching the brain. This treatment is reserved for the most severe cases of CRPS.

Your doctor will discuss all of the available options with you and will tailor treatments to maximize the effectiveness of treatment.

With CRPS, it is especially important to seek treatment early to avoid potentially permanent complications and to help cope with the pain and lead as normal a life as possible.

What About Research Studies for this Condition?

You can see our Current Studies page to find out more about what studies we are currently conducting.