CRPS (Complex Regional Pain Syndrome): Symptoms and Care
Complex regional pain syndrome (CRPS) is a chronic pain condition, usually in an arm or leg, that can follow an injury, surgery, or cast. It can cause burning pain out of proportion to the injury, with swelling and changes in skin color and temperature. This page also answers a common search question: what intense burning pain after a nerve injury may be called, and how that differs from postherpetic neuralgia after shingles. Related hub: nerve pain.
Quick Answer: CRPS
- CRPS involves pain out of proportion to an injury, often with swelling and skin color or temperature change in a limb.
- Intense burning after a nerve injury raises concern for neuropathic pain; CRPS is one pattern clinicians consider when autonomic and motor changes accompany it.
- Diagnosis is clinical (Budapest-style criteria); no single scan proves CRPS.
- Care usually starts with therapy and medicines; blocks or neuromodulation are later options for selected people.
- We do not promise a cure. Spreading infection signs or sudden neurologic collapse need emergency care.
What CRPS Is
Complex regional pain syndrome is ongoing limb pain that is greater than expected for the original injury, with sensory changes and signs such as swelling, sweating change, color or temperature difference, and reduced movement. It was previously called reflex sympathetic dystrophy (RSD) in many clinics. Practical diagnostic and treatment guidance for CRPS is summarized in specialty guidelines [Source]. A clinical overview is also available in the medical literature [Source].
Burning Pain After a Nerve Injury — Where CRPS Fits
People often search for the name of intense burning pain after an injury to a nerve. Burning, shooting, or electric pain after nerve injury is neuropathic pain. CRPS is considered when that pain is out of proportion and clusters with swelling, color or temperature change, sweating change, and movement limits in the limb. Not every nerve injury becomes CRPS. Ordinary recovery pain usually improves as tissues settle; CRPS patterns persist and often include those extra signs.
Burning pain that continues after a shingles rash is usually postherpetic neuralgia—a different diagnosis with a different care path. Post-surgical nerve pain also has its own patterns; share the timeline of surgery, cast, or trauma with your clinician.
CRPS Type 1 vs Type 2
Type 1 occurs without a confirmed injury to a named peripheral nerve. Type 2 follows a confirmed injury to a specific nerve. Both can look similar at the bedside. The label helps describe the history; it does not by itself choose a treatment.
Symptoms
CRPS can show up with many systems involved, which is why early evaluation helps. Common features include:
- Persistent burning or throbbing pain, often out of proportion to the original injury
- Swelling compared with the other side
- Temperature difference—the limb may feel hotter or colder than the opposite side
- Skin color changes—redness, mottling, or pallor
- Sweating changes
- Motor changes—tremor, dystonia (abnormal postures), or weakness
- Trophic changes—brittle nails, hair change, shiny or thin skin
- Pain from light touch (allodynia) and reduced use of the limb
How CRPS Is Diagnosed
CRPS is diagnosed clinically. Validated Budapest criteria combine reported symptoms and examination signs [Source]. X-rays, three-phase bone scan, and EMG can help rule out other causes or support the picture; EMG and nerve studies are referred out when needed. No single test confirms CRPS on its own [Source].
A Short History of the Name
Descriptions of intense burning pain after nerve injury go back to the 1800s. During the American Civil War, Dr. Silas Weir Mitchell wrote about lasting burning pain after nerve wounds and used the word “causalgia.” Later writers used the name reflex sympathetic dystrophy (RSD). In 1994, the International Association for the Study of Pain adopted the name complex regional pain syndrome (CRPS), with type 1 (no confirmed named-nerve injury) and type 2 (confirmed named-nerve injury). The modern name stresses that symptoms involve more than the sympathetic nervous system alone.
What May Be Going On in the Body
The exact cause of CRPS is not fully known. Research points to several processes working together—not a single switch:
Nerve-driven inflammation
Injured nerves can release inflammatory messengers that increase blood flow and swelling and keep the area extra sensitive long after the original tissue should have healed. Immune chemicals can also sensitize nearby nerves and amplify pain signals.
Central sensitization
Over time, the spinal cord and brain can become over-responsive. Light touch or mild temperature change may hurt (allodynia). Pain can feel larger than the original injury site. This helps explain why CRPS can spread beyond the first spot.
Autonomic (involuntary nerve) changes
The nerves that control blood flow and sweating can become abnormally linked to pain pathways. The limb may turn hot and red at times, or cold and bluish at other times, with sweating changes. Uneven blood flow can add to discomfort.
Why only some people develop CRPS
Most sprains, fractures, and surgeries heal without CRPS. Susceptibility may involve genetics, immune response differences, prior nerve injury, and stress amplifying pain perception—stress does not mean the pain is “imagined.” CRPS is more often reported in women, which has led researchers to study hormonal influences. The injury severity alone does not predict who is affected; the body’s response afterward matters more.
What Injuries Can Precede CRPS?
Many events have been linked, including fractures (a common trigger), sprains, surgery (even routine procedures), cuts or burns, and prolonged immobilization such as casting. In uncommon cases, symptoms appear without a clear starting event. Any injury has the potential to precede CRPS in a susceptible person—but most injuries do not.
Remission, Relapse, and Realistic Goals
People often ask whether CRPS can go away. Some people have long stretches when symptoms are much quieter (remission). Symptoms can return later after a new injury, illness, or stress (relapse). We do not describe CRPS as cured, and we do not promise remission. Early recognition and steady therapy still matter because delayed care can make patterns harder to reverse. Maintenance plans—therapy, coping skills, and, for selected people, neuromodulation—aim at function and stability, not guaranteed permanence.
Care Options (Stepwise)
Treatment works best when it is interdisciplinary and starts early. Goals are to reduce pain and restore use of the limb. Responses vary; no treatment guarantees a result.
Rehabilitation and medicines
Physical and occupational therapy—desensitization, graded motor imagery, mirror therapy, and gradual return to use—are central. Medicines for nerve pain may be used when appropriate. Psychological support for coping skills can help people stay engaged in rehabilitation.
Interventional options
For selected people, a sympathetic nerve block (stellate ganglion for the arm, lumbar sympathetic for the leg) may be discussed to reduce pain enough to advance therapy. Spinal cord stimulation devices are FDA-approved (PMA) and may be considered after a successful trial in carefully selected cases; dorsal root ganglion (DRG) stimulation is FDA-approved for CRPS of the lower limbs. See neuromodulation resources on this site. These are options, not promised cures.
When to Seek Urgent or Emergency Care
Call 911 or go to the nearest emergency room for chest pain, trouble breathing, signs of rapidly spreading infection with fever, sudden severe weakness, or new bladder or bowel loss with spine symptoms.
Worsening CRPS symptoms that limit sleep or therapy still deserve timely outpatient evaluation even when emergency signs are absent.
CRPS Care at SpinePain Solutions
At SpinePain Solutions, Dr. Amit Sharma, Chief, Division of Pain Medicine at Good Samaritan University Hospital, evaluates CRPS and related neuropathic pain patterns and coordinates therapy-first plans, with interventional options when they fit. Offices in Bay Shore, Commack, and Farmingdale (office locations). Call or text 631-310-0000.
Dr. Amit Sharma & our minimally invasive pain & spine team.
Frequently Asked Questions
What is the intense burning pain after a nerve injury called?
Intense burning pain after a nerve injury may be neuropathic pain. When pain is out of proportion to the injury and comes with swelling, color or temperature change, and movement limits in a limb, clinicians consider complex regional pain syndrome (CRPS). Burning after shingles is a different pattern—see postherpetic neuralgia.
When is CRPS-related pain an emergency?
Call 911 or go to the nearest emergency room for sudden severe weakness, chest pain, trouble breathing, signs of a spreading infection (fever with rapidly worsening redness), or new loss of bladder or bowel control with spine symptoms. Routine CRPS clinic visits are not for those emergencies. Call SpinePain Solutions at 631-310-0000 for non-emergency questions.
What is the difference between CRPS type 1 and type 2?
Type 1 occurs without a confirmed injury to a named peripheral nerve. Type 2 follows a confirmed injury to a specific nerve. Both can cause burning pain, swelling, and skin changes; the distinction is about whether a discrete nerve injury is documented.
How is CRPS diagnosed?
CRPS is a clinical diagnosis using symptom and sign criteria (often called the Budapest criteria). X-rays, bone scans, and EMG help look for other explanations and may support the picture, but no single test proves CRPS.
What treatments are tried first for CRPS?
Care usually starts with physical and occupational therapy (including desensitization and graded use of the limb), medicines when appropriate, and psychological support for coping. Interventional options such as sympathetic blocks or neuromodulation are considered later for selected people—not as a promised cure.
Is burning pain after shingles the same as CRPS?
No. Pain that continues after a shingles rash is typically postherpetic neuralgia. It can burn and be severe, but the pattern and exam differ from CRPS. See our postherpetic neuralgia guide.
Where can I get evaluated on Long Island?
SpinePain Solutions evaluates CRPS and related neuropathic pain at Bay Shore, Commack, and Farmingdale. Call or text 631-310-0000.
Dr. Amit Sharma & our minimally invasive pain & spine team.
Medical References
- Harden RN, et al. Validation of proposed diagnostic criteria (the “Budapest Criteria”) for Complex Regional Pain Syndrome. Pain. 2010. PMID 20493633.
- Harden RN, et al. Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th Edition. Pain Med. 2022. PMID 35687369.
- Birklein F, Dimova V. Complex regional pain syndrome. BMJ. 2015. PMID 26224572.
