Complex Regional Pain Syndrome (CRPS): What It Is and How It's Treated

Complex regional pain syndrome — CRPS — is one of the most challenging chronic pain conditions in medicine. It produces pain that is often described as burning, stabbing, or electrical, typically in an arm or leg, and the pain is dramatically out of proportion to whatever initially caused it. A minor fracture, a sprain, a surgical incision — injuries that should heal in weeks — instead trigger an ongoing pain response that can persist for months or years.

If you or someone you care about is dealing with CRPS, understanding the condition is genuinely important. It's frequently misdiagnosed, often misunderstood, and many patients spend months searching for answers before getting an accurate diagnosis.

What Is CRPS?

CRPS (previously called reflex sympathetic dystrophy, or RSD) is a chronic pain condition that usually develops after an injury, surgery, or other tissue trauma. It most commonly affects a single limb, though it can spread.

The hallmark of CRPS is pain that is far greater than expected for the original injury. A patient might break a wrist, undergo appropriate treatment, and then develop excruciating, unrelenting pain in that hand and forearm long after the fracture has healed. The nervous system essentially malfunctions — instead of returning to normal after the injury resolves, it continues generating intense pain signals.

There are two types:

CRPS Type I (formerly RSD): No confirmed nerve injury. This is the more common form, accounting for roughly 90 percent of cases. It develops after an event such as a fracture, sprain, surgery, or even immobilization in a cast.

CRPS Type II (formerly causalgia): Develops after a confirmed nerve injury. The symptoms are similar, but there is documented nerve damage.

Recognizing the Symptoms

CRPS presents with a characteristic cluster of symptoms that go beyond pain:

Pain. Intense burning, throbbing, or shooting pain, often described as the worst pain the patient has ever experienced. Light touch that would normally be painless — clothing against the skin, a breeze, a bedsheet — can trigger severe pain (a phenomenon called allodynia).

Sensory changes. Increased sensitivity to touch and temperature. Some patients also develop areas of numbness.

Swelling. The affected limb often appears swollen, particularly in the early stages.

Skin changes. The skin over the affected area may change color (red, blue, purple, or mottled), temperature (warmer or cooler than the other limb), and texture (shiny, thin, or excessively sweaty).

Motor changes. Weakness, tremor, decreased range of motion, and in advanced cases, muscle atrophy and joint stiffness. Some patients develop dystonia (involuntary muscle contractions).

Nail and hair changes. Altered nail and hair growth patterns in the affected area — faster or slower growth, brittleness, or changes in texture.

These symptoms don't all appear simultaneously. CRPS often progresses through stages, though this progression isn't uniform for every patient.

Why Does CRPS Happen?

The short answer is that we don't fully understand why some people develop CRPS and others with identical injuries do not. What we do know involves several overlapping mechanisms:

Neurogenic inflammation. Nerve fibers in the affected area release inflammatory chemicals (substance P, CGRP) that cause swelling, warmth, and skin changes. This inflammation persists beyond the normal healing timeline.

Central sensitization. The spinal cord and brain become hyperresponsive to signals from the affected limb. Normal sensory input gets amplified and interpreted as pain.

Sympathetic nervous system dysfunction. The sympathetic nervous system — which normally regulates blood flow, sweating, and fight-or-flight responses — becomes abnormally coupled to pain pathways. This explains many of the temperature, color, and sweating changes seen in CRPS.

Immune and autoimmune factors. Emerging research suggests that CRPS may involve autoimmune components, with the body's immune system attacking its own tissues in the affected area.

Psychological factors. Stress, anxiety, and catastrophizing about pain don't cause CRPS, but they can amplify and perpetuate the symptoms through their effects on central sensitization. This is true of all chronic pain conditions, and it does not mean CRPS is "in your head."

Diagnosis

There is no single test for CRPS. Diagnosis is clinical, based on the Budapest Criteria:

1. Continuing pain disproportionate to the inciting event
2. At least one symptom in three of four categories: sensory, vasomotor (skin color/temperature), sudomotor/edema (sweating/swelling), motor/trophic (movement/skin/nail/hair changes)
3. At least one sign in two or more of those categories at the time of evaluation
4. No other diagnosis that better explains the signs and symptoms

Imaging and nerve studies may be used to rule out other conditions but are not required for diagnosis. A bone scan, MRI, or thermography may show supporting findings but are not diagnostic on their own.

Early diagnosis matters enormously. Patients who receive appropriate treatment within the first few months after symptom onset have significantly better outcomes than those diagnosed later.

Treatment Options

CRPS treatment is multimodal — no single treatment is sufficient on its own. The most effective approach combines physical rehabilitation, medications, psychological support, and sometimes interventional procedures.

Physical and Occupational Therapy

This is the single most important component of CRPS treatment. The affected limb needs to move, even though movement is painful. Immobilization — the natural response to pain — leads to further stiffness, weakness, and worsening of the condition.

Graded motor imagery (GMI) is a specialized approach that works by retraining the brain's representation of the affected limb. It progresses through stages: recognizing left vs. right images of the limb, imagining moving the limb, and then mirror therapy (watching the unaffected limb's reflection to "trick" the brain into processing normal movement of the affected side).

Desensitization involves gradually exposing the affected area to different textures and sensations, starting with what's tolerable and slowly progressing. Over time, this helps recalibrate the nervous system's response to touch.

Functional restoration focuses on gradually returning to normal use of the affected limb in daily activities.

Medications

Neuropathic pain medications (gabapentin, pregabalin, duloxetine, amitriptyline) are commonly used for the nerve-related pain component of CRPS.

Anti-inflammatory agents — both NSAIDs and sometimes short courses of oral corticosteroids early in the disease course — can help manage the inflammatory component.

Bisphosphonates (medications typically used for osteoporosis) have shown benefit in some CRPS patients, possibly by reducing the abnormal bone metabolism seen in the condition.

Topical treatments — lidocaine patches, capsaicin cream, compounded topical analgesics — can provide localized relief without systemic side effects.

Low-dose naltrexone (LDN) is being explored for CRPS based on its anti-inflammatory and immune-modulating properties. Evidence is still preliminary but growing.

Medical Cannabis

CRPS involves several pathological processes — neurogenic inflammation, central sensitization, neuropathic pain, sleep disruption, and often anxiety and depression — that cannabinoids have been shown to address.

While there are no large clinical trials specifically studying cannabis for CRPS, the mechanistic rationale is strong, and many CRPS patients report meaningful benefit:

• THC can reduce central sensitization and modulate pain signal transmission
• CBD addresses neurogenic inflammation and may calm an overactive immune response
• Topical cannabis products applied to the affected area can interact with local cannabinoid receptors without systemic effects
• Sleep improvement from evening cannabis use supports the nervous system recovery that is critical in CRPS

A reasonable approach: CBD-dominant or balanced (1:1) products during the day for anti-inflammatory and anxiolytic effects, with a THC-containing product in the evening for pain and sleep. Topical cannabis products can be applied directly to the affected area as an adjunct.

Interventional Procedures

Sympathetic nerve blocks — injections that temporarily block sympathetic nerve activity in the affected area — can provide significant relief for some patients and help determine whether the sympathetic nervous system is driving their symptoms.

Spinal cord stimulation — a device implanted along the spinal cord that delivers electrical pulses to interrupt pain signals — has shown benefit in CRPS patients who haven't responded to more conservative treatments.

Intrathecal drug delivery — a pump that delivers medication directly to the spinal fluid — is reserved for severe, refractory cases.

Living With CRPS

CRPS is a condition where early, aggressive, multimodal treatment produces the best outcomes. Many patients improve significantly with appropriate care, and some achieve complete resolution of symptoms.

For patients with persistent CRPS, the focus shifts to functional improvement — doing more despite the pain, maintaining mobility in the affected limb, managing the psychological impact, and finding the medication and therapy combination that provides the best quality of life.

If you're in Florida and dealing with chronic pain after an injury that seems disproportionate to what you'd expect, or if you've been diagnosed with CRPS and are looking for additional treatment options including medical cannabis, [schedule a consultation with Coral Health](/booking). We'll review your case and help you build a comprehensive management plan.