Complex regional pain syndrome (CRPS, once called RSD) is pain far worse than the injury explains. It sits in a limb that has changed color, temperature or texture. It is real. It can be treated. And it is treated best early.
What is complex regional pain syndrome (CRPS)?
CRPS, still often called RSD, starts after an injury, sometimes a minor one. The sympathetic nervous system (the nerves that control blood flow and sweating) and the pain pathways get locked into a loop that feeds itself.
It is diagnosed by exam. No single test confirms it. That is part of why patients are so often not believed before they reach a pain specialist.
What are the symptoms of CRPS?
- Burning pain far greater than the original injury warranted.
- Skin color change (red, purple or blotchy) and a temperature difference between limbs.
- Swelling, changes in sweating, and changes in hair or nail growth.
- Extreme sensitivity, where light touch or a bedsheet hurts.
- Stiffness and loss of use of the limb.
How is CRPS treated?
- Early treatment matters more here than in almost any other pain condition. Delay makes it harder.
- Stellate ganglion block for the arm, or lumbar sympathetic block for the leg.
- Intensive physical therapy. The blocks exist to make movement possible.
- Nerve pain medication, and ketamine in chosen cases.
To be assessed, call us or request an appointment. If this began with a crash or a fall, see accident and injury care.
Why is CRPS so often missed?
The diagnosis is missed because doctors look for something dramatic. CRPS often starts quietly. A limb hurts more than it should after a minor injury. There is slight swelling and a color change that is easy to blame on bruising.
It is also missed because no test confirms it. CRPS is diagnosed by exam, using the Budapest criteria (a standard checklist of signs and symptoms). When no investigation comes back positive, that is often taken as evidence against it. Patients are told the pain is out of proportion. But that is exactly the main sign of CRPS, not a reason to doubt them.
Will CRPS ever go away?
The outcome depends heavily on how early treatment starts. When it is caught and treated in the first few months, a large share of patients get much better. Left for a year, it gets far harder to turn around.
The purpose of sympathetic blocks is not just pain relief. They open a window when the limb can be moved and used, because getting back normal use is what really reverses the process. A block without intensive rehab afterward wastes most of its value.
When this becomes urgent
CRPS itself is not an emergency, but the window for treatment that works is. Pain out of proportion with color, temperature or swelling change in a limb after an injury should be checked within weeks, not months. Delay is the biggest single factor in a poor outcome.
Common questions
Is CRPS permanent?
Not always, especially when treated early. Outcomes are far better when it is caught in the first months.
Why do people keep telling me it is in my head?
Because there is no blood test and the symptoms look dramatic. It is a known condition with signs a doctor can see and measure. Being told otherwise is a failure of diagnosis, not of your story.
What causes CRPS?
CRPS starts after an injury, and that injury is sometimes a minor one. Then the sympathetic nervous system and the pain pathways lock into a loop that keeps itself going. That is why the pain grows far beyond what the original injury should cause. It often begins quietly, with a limb that hurts more than it should, slight swelling, and a color change that looks like bruising.
What is the other name for CRPS?
CRPS is still often called RSD, short for reflex sympathetic dystrophy. Both names describe the same condition: pain far out of proportion to an injury, in an arm or leg that has changed color, temperature or texture. Whichever name you have heard, it is diagnosed by exam, not by a single test. And it is treated best early.
How painful is CRPS?
CRPS causes burning pain far greater than the original injury warranted. Many people become so sensitive that light touch, or even a bedsheet, hurts. The limb can also swell, sweat differently, stiffen and lose use. Being told your pain is out of proportion is not a reason to doubt you. That mismatch is the main feature of the condition, not evidence against it.
Sources
- Ferraro MC et al. Complex regional pain syndrome: advances in epidemiology, pathophysiology, diagnosis, and treatment. The Lancet. Neurology, 2024. PubMed 38631768
- Taylor SS et al. Complex Regional Pain Syndrome: A Comprehensive Review. Pain and therapy, 2021. PubMed 34165690
- Harden RN et al. Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th Edition. Pain medicine (Malden, Mass.), 2022. PubMed 35687369
- Lima Pessôa B et al. Complex Regional Pain Syndrome: Diagnosis, Pathophysiology, and Treatment Approaches. Cureus, 2024. PubMed 39850174
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