Complex regional pain syndrome (CRPS) is a nervous system condition that usually follows an injury and leaves a limb in pain far out of proportion to the damage. The limb may be tender, swollen, or changed in color or temperature. Earlier diagnosis and treatment are linked with better odds of improvement, according to the Cleveland Clinic.
If your pain has outlasted the injury, you’ve probably heard some version of "it should be better by now." Maybe you’ve even started to wonder whether you’re imagining it. You’re not. CRPS has a name, a set of recognized signs, and a growing body of research behind it.
This page is for you if you’ve just been given the diagnosis, or if you suspect it and want the basics before your next appointment. We’ll go at your pace, and hope is a reasonable place to start.
What does CRPS feel like?
CRPS usually shows up in one arm or leg as pain that is stronger and lasts longer than the original injury would explain. The National Institute of Neurological Disorders and Stroke describes it as a condition that "usually affects a limb (an arm or a leg) after an injury and causes ongoing pain that is much stronger even after the injury has healed."
The limb is often very sensitive. According to the NINDS, even light touch may feel painful, and normal pain elsewhere in the body may feel much more intense than usual.
The limb can also look different. The NINDS says it may show changes in skin, temperature, nails, or hair, along with unusual sweating.
Over time, some people also notice weakness, tremors, or stiffness in the muscles and joints, and trouble moving the limb. If you’ve been describing these things to doctors and getting blank looks, you’re in good company.
What is happening in the nervous system?
In CRPS, the nervous system keeps sending pain and body-regulation signals after the tissue has healed. Researchers don’t yet agree on every detail. The Merck Manual says the mechanism "is unclear, but peripheral nociceptor and central sensitization and release of neuropeptides (substance P, calcitonin gene-related peptide) help maintain pain and inflammation."
Think of a smoke alarm that keeps blaring after the fire is out. It isn’t silent, and it isn’t quite broken. It’s too sensitive, and it doesn’t know when to stop.
That’s why CRPS isn’t simply a problem in the hand or the foot. The nerves that carry pain, the nerves that control blood flow and sweating, and the brain and spinal cord that coordinate them are all involved. The autonomic nervous system runs the things you never think about, like temperature, circulation and sweating, and when it’s out of balance you get the skin and temperature changes many patients report.
Anyone who tells you they have the whole explanation is going further than the science does. The Merck Manual itself calls the mechanism unclear.
What are the two types of CRPS?
CRPS is divided into Type 1 and Type 2, based on whether a specific nerve was damaged. The symptoms look the same. What differs is the history behind them.
| Type 1 | Type 2 | |
|---|---|---|
| What started it | Illness or injury with no specific nerve damage | Damage to a specific nerve |
| Older name | Reflex sympathetic dystrophy (RSD) | Causalgia |
| Can tests confirm the nerve injury? | Usually not | Nerve injuries can usually be detected |
The NINDS puts the split this way: "Type 1 happens after illness or injury that doesn’t cause any specific nerve damage." Type 2 follows damage to a specific nerve. The older names are still in use, so you may see RSD on records or in searches. It’s the same family of condition.
Type 1 is the one doctors usually can’t confirm with a scan or a nerve test, which is a large part of why people wait so long for an answer.
Who gets CRPS, and what starts it?
Anyone can develop CRPS, though it’s uncommon. The Cleveland Clinic says it "affects about 200,000 people every year in the United States" and that the peak onset is around age 40. Children can get it too. The NINDS notes that Type 1 is more common in girls and in children age 12 or older.
The Cleveland Clinic says that in more than 90% of cases, CRPS results from nerve trauma or injury to the affected limb.
Some patients can name the moment it began. Others can’t, and that’s normal too. If you want to look more closely, our pieces on how people get CRPS and CRPS triggers and what could have started it go through the possibilities one by one. Neither asks you to find someone or something to blame.
How is CRPS diagnosed?
CRPS is diagnosed mainly from your history and a physical exam, not from a single test. The Merck Manual says it’s diagnosed when a patient has "continuing pain beyond that explained by dysfunction of a single nerve and that is disproportionate to any original tissue damage." The clinician also looks for the sensory, color, temperature, sweating and movement changes described above.
There’s no blood test that settles it. The NINDS notes that doctors "can detect nerve injuries linked to CRPS type 2 but usually cannot confirm CRPS type 1." So a clinician who knows what to look for matters more than any machine.
If you want to prepare for that visit, our guide to how CRPS is diagnosed walks through what an exam usually involves. It also covers what to bring with you.
Why does early care matter?
The sooner CRPS is recognized and treated, the better the chance that symptoms improve. The Cleveland Clinic says so directly: "The sooner you receive a diagnosis and treatment, the more likely your symptoms will improve." Valley Children’s Pediatric HealthHub says the same of treatment generally: "The sooner you get any type of treatment, the more likely you are to get better."
Part of the reason is practical. A limb that hurts to touch tends to get moved less, and a limb that moves less can get stiffer and weaker. Early therapy aims to interrupt that cycle. Spotting who is at risk is also getting better: The Lancet Neurology00076-0/abstract) reports that "Early identification of individuals at high risk of CRPS is improving, with several risk factors established and some others identified in prospective studies during the past 5 years."
None of this is a reason to panic. Early doesn’t mean a race, and it doesn’t mean that someone years into CRPS has run out of options. People at every stage still have questions worth asking a clinician. If you have symptoms now, getting them looked at now is the kind choice for yourself.
What does the course of CRPS look like over time?
It varies a great deal, and anyone who hands you a single timeline is guessing. The NINDS says pain and trouble with everyday tasks "can improve over time, but most people with CRPS still have some feelings of pain after a year." The Cleveland Clinic adds that CRPS recurs in about 10% to 30% of people. Children tend to do better, since the NINDS says CRPS in children "usually gets better within 6-8 months, although some children may have symptoms that come back."
You may also wonder whether it spreads. Our piece on whether CRPS spreads looks at what people notice and what it can mean. It’s worth knowing about, but it doesn’t describe what will happen to you.
Healing takes time, and everyone moves at a different pace. Dr. Katinka often tells her patients, "The body never lies, but it does whisper before it screams." If you’d like to see what a good outcome can look like without false promises, read what CRPS remission looks like.
How does The Spero Clinic look at CRPS?
We start from the nervous system. Our founder, Dr. Katinka van der Merwe, DC, built The Spero Clinic in Fayetteville, Arkansas, around a simple idea: treat the nervous system, not just the symptom. We offer intensive, in-person neurologic rehabilitation for people with complex chronic pain, many of whom have been told there are no more options.
That doesn’t mean we think conventional care has no value. Appropriate medical evaluation matters, and nothing we do replaces it or emergency care. It means that when pain persists, we look at how the central and autonomic nervous system are regulating the whole body, not only the sore limb.
We can’t promise any particular result, and no responsible clinic can. What we can do is listen to your whole story, tell you honestly whether we think we’re a fit, and explain what the commitment involves. Our page on CRPS at The Spero Clinic and our article on how we treat CRPS lay out how we work. For the longer background read on the condition, see everything to know about CRPS.
What are the most common mistakes after a CRPS diagnosis?
The first is waiting to see if it passes on its own. Some mild cases do settle, but if the pain is out of proportion to the injury and you also see skin, swelling or temperature changes, it’s worth having someone look at it.
The second is protecting the limb so completely that you stop using it. It makes sense to want to avoid touch and movement when everything hurts. Still, ask your clinician or therapist how to keep gentle movement going, because a guarded limb can stiffen.
The third is reading one frightening statistic and deciding it’s your future. Numbers about recurrence describe groups of people, not you. Take them as information and bring your questions to a clinician.
The last is blaming yourself. CRPS doesn’t come from doing something wrong or from weakness. It’s a recognized condition, and people who have it deserve to be believed.
Frequently asked questions
Will CRPS ever go away?
Sometimes it improves a great deal, and sometimes it doesn’t fully resolve. The NINDS says pain and daily difficulties can improve over time, but most people still have some pain after a year. The Cleveland Clinic says CRPS recurs in about 10% to 30% of people. Individual outcomes vary widely.
What is the most common cause of CRPS?
An injury to the affected limb is the most common starting point. The Cleveland Clinic says that in more than 90% of cases, CRPS results from nerve trauma or injury that damages the thinnest sensory and autonomic nerve fibers. Many people can’t point to one moment, and that’s common too.
How serious is CRPS?
It ranges widely. The NINDS says that in more severe or long-lasting cases, a person with CRPS can’t work or do their usual daily activities, while children usually improve within 6 to 8 months. A clinician who examines you can tell you where you sit on that range.
Is CRPS classified as a disability?
Whether CRPS counts as a disability depends on how much it limits your daily activities and work, and agencies and insurers make that decision case by case. We can’t say how yours would be judged. Ask your doctor to document your symptoms and limitations in detail.
What can you do today?
Write down what you’re feeling, starting with where the pain is, what touches or movements set it off, and any changes in color, temperature, swelling or sweating. Add dates, and take photos if the limb looks different from one day to the next. Bring that record to your next appointment, because it gives a clinician something concrete to work from, and read our guide to how CRPS is diagnosed so you know what to expect. Hope is still within your reach, and when you’re ready, you can schedule a free discovery call with us at The Spero Clinic and ask whatever hard questions you have.
