Understanding Complex Regional Pain Syndrome (CRPS) and How to Manage It

What is Complex Regional Pain Syndrome (CRPS)?

Complex Regional Pain Syndrome (CRPS) is a chronic pain condition which usually starts after an injury, like a broken bone or surgery, but the pain lasts longer and is much stronger than what you’d expect from the original injury. CRPS most often affects an arm, leg, hand, or foot.

Sometimes, CRPS can happen without a clear injury. While CRPS is rare—about 50,000 new cases happen every year in the U.S.—it might be missed by doctors because its early signs can look like normal post-injury inflammation.

Types of CRPS

There are two types of CRPS:

• Type 1 (Reflex Sympathetic Dystrophy): Happens without a clear nerve injury.
• Type 2 (Causalgia): Happens when there is a confirmed nerve injury.

Sometimes, people are first diagnosed with Type 1, but later tests show nerve damage, and the diagnosis changes to Type 2.

What Are the Symptoms of CRPS?

Symptoms can be different for each person but often include:

• Pain from light touch or even a breeze
• Persistent swelling in the injured limb
• Skin that feels very hot or cold
• Changes in skin color (red, purple, pale)
• Hair and nails growing differently
• Muscle spasms, tremor or weakness

Phases of CRPS

Doctors sometimes talk about CRPS in phases, though not everyone goes through all of them

• Early (Acute) Phase: The affected limb is red, warm, and swollen—signs of inflammation.
• Later (Chronic) Phase: The limb may feel cool, stiff, or shrunken. Swelling may go down, but pain and sensitivity often get worse.

Some people move through these phases within a year; others may stay in one phase longer or have a cool, shrunken limb from the start.

What Are the Risk Factors for CRPS?

We know that:

• Increased, severe pain after an injury or surgery.
• Some people might have genes that increase their risk.
• Women get CRPS about three times more often than men.
• Feeling like a cast or bandage is too tight after an injury can be a risk factor.

Experts believe that in CRPS, the body’s pain system becomes overly sensitive and gets stuck in a cycle of pain.

What are the causes of CRPS?

CRPS involves many mechanisms. There are 3 general potential causes of CRPS which may contribute more or less in a given patient:

• Inflammation is important, especially early on
• Nerve injury, potential compression or scarring around a nerve
• Activation of the sympathetic or “fight-or-flight” part of the nervous system
   

How Do Doctors Diagnose CRPS?

There isn’t one single test for CRPS. Instead, doctors use:

• Your story of how and when the pain started
• A physical exam
• The Budapest Criteria—a checklist of symptoms pain doctors use
• Nerve block tests that can help pinpoint the pain source
• Special imaging scans like MR neurography that show tiny nerve changes. For example, Stanford researchers have used magnetic resonance neurography (MRN) to detect nerve abnormalities, as shown in Figure 1 from a 2021 study published in Frontiers in Pain Research.
   

How Is CRPS Treated?

CRPS treatment often needs many types of clinicians working together. The goal is to reduce pain, improve movement, and support emotional health.

In select cases where nerve injury is suspected, SHC Pain Medicine physicians in collaboration with physicians in the Departments of Surgery and Radiology, meet as a multispecialty team to develop a multi-modal plan for patients as part of our nerve injury program.

Medications

• Steroids or other anti-inflammatory drugs: Can help lower inflammation early on.
• Bisphosphonates: Medicines that may reduce inflammation and help heal bones.
• Anti-neuropathic drug: Medications used for the treatment of nerve-related pain such as gabapentin or nortriptyline can help decrease pain signals.
• Medications that lower the sympathetic nerve system response
• Ketamine: Sometimes given through IV or cream to "reset" pain signals. About one-third of patients feel lasting relief.
   

Procedures and Surgery

• Sympathetic Nerve Blocks: Injections that calm the nerves (fight-or-flight system) that contributes to pain.
• Nerve blocks: Nerve blocks involve injection of local anesthetic “numbing” medications that last 6-8 hours and can help diagnose a nerve issue contributing to CRPS.
• Peripheral nerve stimulators or nerve surgery: Peripheral nerve stimulators (PNS) can be implanted to “override” signals from overactive nerves. In some cases if a trapped nerve is causing pain it can be surgical released.
• Spinal Cord Stimulation: A device placed near the spine sends electrical signals to lower pain.
   

Movement and Therapy

• Physical and Occupational Therapy: Moving the limb helps prevent CRPS from getting worse. The use of mirror-therapy and graded motor imagery can help regain functional use of the CRPS limb.
• Hand Therapy: Important for people with pain in their hands or arms.
   

Emotional Support

• Pain Psychology: Mindfulness and stress-management techniques can help calm the nervous system and reduce pain flare-ups.

Hope for People with CRPS

CRPS is a complicated condition, but new research and better imaging tools are helping doctors diagnose it faster and more accurately. Treatments are becoming more tailored to each person’s pain.

“Every patient with CRPS is different,” Stanford’s Dr. Vivianne Tawfik says. “But the earlier we catch it—and understand why it happens—the better the chance we have to help people heal.”

Presented in partnership with Stanford Health Library
 

Stories

Education

• What is CRPS? (Stanford Health Care)
• Emerging Therapies for CRPS and The National Pain Strategy with Sean Mackey (Video)