Complex regional pain syndrome (CRPS) is a chronic pain condition that usually affects an arm or a leg after an injury, with pain far stronger than the injury explains. Doctors diagnose it by examining you and ruling out other causes. It has two types, and RSD is the older name for Type 1, according to Altru.
You’ve just been handed a name. Chances are you have more questions than the appointment had time for, and maybe you’ve also spent months being told the pain was in your head or that it would settle down once the injury healed. You are not crazy. These symptoms are real, and they make sense when we look at the nervous system.
This is education, not a substitute for a medical evaluation. If your pain is new, severe, or spreading, get examined by a clinician first.
What is complex regional pain syndrome?
CRPS is pain that outlasts and outweighs the injury that started it. According to the National Institute of Neurological Disorders and Stroke, it is a condition that usually affects a limb after an injury and causes ongoing pain that is much stronger even after the injury has healed. The limb is often so sensitive that even light touch can hurt.
The skin, temperature, nails, or hair of that limb may change, and sweating can be unusual. Over time, some people also develop weakness, tremors, or stiffness. A clinician can measure those changes, which matters if anyone has ever suggested you were imagining them.
The pain usually stays in one limb but can sometimes spread, and the NHS calls CRPS a poorly understood condition. It typically follows an injury, a surgery, a stroke or a heart attack, says Altru in material from the Mayo Foundation.
So is it real? Yes. The Merck Manual describes it as an array of chronic neuropathic pain conditions in which the pain is more severe and longer-lasting than would be expected from the initial tissue damage. It is also easy to miss. Many cases may go undiagnosed or be misdiagnosed, the NHS notes, which makes it hard to say how common CRPS is. That is part of why so many patients reach a diagnosis after years of being doubted. Your symptoms made sense all along. The label just took its time.
What are Type 1 and Type 2?
The two types are separated by one question: was a specific nerve damaged? The symptoms look the same, so the difference shows up in the history and the testing, not in how the pain feels.
| CRPS Type 1 | CRPS Type 2 | |
|---|---|---|
| What starts it | An illness or injury that didn’t cause specific nerve damage | Damage to a specific nerve |
| Older name | Reflex sympathetic dystrophy (RSD) | Not covered here |
| How common | About 90% of people with CRPS, per Altru | The smaller share |
| What testing shows | Nerve injury usually can’t be confirmed | Nerve injury can be detected |
Type 2 follows a distinct nerve injury, per Altru’s Mayo-sourced page. If your records say “CRPS I” or “CRPS-1,” that’s Type 1. Neither type is worse by definition. Both can be severe, and both deserve a real plan.
Why do some records still say RSD?
RSD stands for reflex sympathetic dystrophy, which Altru lists as the other name for Type 1. You’ll still see it in older books, on patient group websites, and in what people type into a search box. If a relative or a forum calls it RSD, they’re talking about the same condition. I use both names in my own writing because patients meet both.
How is CRPS diagnosed?
There is no single blood test or scan that confirms CRPS. Diagnosis rests on your history and an examination, plus tests that rule out other explanations. The NHS puts it plainly: diagnosing CRPS can be difficult because it involves having tests to rule out other possible causes.
Clinicians work from a checklist. The Merck Manual frames the starting point this way: patients have continuing pain beyond that explained by dysfunction of a single nerve and that is disproportionate to any original tissue damage. After that, the examiner looks for a pattern of sensory, temperature, skin, swelling, and movement changes.
We aren’t listing every item of the checklist here, because it is meant to be applied by a clinician who is examining you. If you suspect CRPS and haven’t been formally assessed, ask whoever you see whether they’ve applied the standard diagnostic checklist.
One more thing you may read online. An older idea that CRPS moves through three fixed stages is no longer in wide use, according to Wikipedia’s summary of the literature. So if a page tells you exactly where you’ll be in six months, be wary.
Why does one injury lead to CRPS and another doesn’t?
Nobody can yet say exactly why one person develops CRPS after an injury and another doesn’t. The NHS says the cause is unknown, but for many people it’s thought to be the result of the body reacting abnormally to an injury.
Many cases follow a forceful trauma to an arm or a leg, Altru says. Risk factors have been studied too, and a 2024 review in The Lancet Neurology00076-0/abstract) says early identification of people at high risk is improving, with several risk factors established. The abstract doesn’t list them, so we won’t guess.
We’ve also seen patients whose history includes conditions like POTS or Ehlers-Danlos syndrome. Those are separate diagnoses that can coexist, which is covered in our post on how the Spero Clinic treats chronic pain conditions.
How does the nervous system fit in?
The medical framing and the nervous-system framing aren’t opposites. They describe the same thing from different distances. The Merck Manual says the pathophysiology is unclear, but peripheral nociceptor and central sensitization and release of neuropeptides (substance P, calcitonin gene-related peptide) help maintain pain and inflammation.
In plain language, “sensitization” means the nerves in the limb, and the brain and spinal cord that receive their signals, turn the volume up and don’t turn it back down. That is why a light touch can hurt. It is also why the pain can spread.
At The Spero Clinic, we treat the nervous system, not just the symptom. In Fayetteville, Arkansas, that means an intensive, in-person neurologic rehabilitation program designed to support balance and function across the central and autonomic nervous system. It doesn’t replace a proper medical evaluation, and we can’t promise any specific result for any one person.
Our page on CRPS and our earlier guide, everything to know about CRPS, cover how we treat it. This page sticks to the formal terms.
What does healing time look like with CRPS?
It depends on the person, and nobody can predict yours. 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.
In some people the signs and symptoms go away on their own, and in others they persist for months to years, says Altru. For children, the NINDS says CRPS usually gets better within 6 to 8 months, although some children have symptoms that come back and need more physical therapy.
Healing rarely runs in a straight line, so judge it over months, not days. Some people move slowly and some move in steps. A bad week doesn’t erase the progress before it. If you’re a parent watching a child go through this, we wrote about what it’s like to be the parent of a child in daily pain.
Common mistakes after a CRPS diagnosis
The most common mistake is waiting. Treatment is likely to be most effective when started early, according to Altru, so a long stretch of “let’s see if it settles” can cost you time. If a clinician has dismissed your symptoms, ask for a second opinion.
A second mistake is believing the first web page you read. Some pages promise a definite outcome, and others describe a fixed timeline that current references no longer support. A trustworthy source tells you what is known, what isn’t, and who can answer the rest.
The third is going through it alone. Many patients feel guilty, isolated, or ashamed, and they hide how bad it has gotten. Tell someone close to you what a bad day actually looks like. A caregiver who understands can help you keep records and show up to appointments.
FAQ
Will my CRPS ever go away?
For some people it fades on its own, and for others it lasts months to years. The NINDS notes that most people still have some pain after a year, though daily function can improve. Early treatment tends to matter, and no one can promise your outcome.
What triggers complex regional pain syndrome?
Usually an injury, surgery, stroke, or heart attack. The exact reason it develops in some people isn’t known. The NHS says it’s thought, for many, to be the body reacting abnormally to an injury.
Is complex regional pain syndrome real?
Yes. It appears in clinical references such as the Merck Manual and NHS guidance, with measurable changes in skin, temperature, and movement. It is often missed or misdiagnosed, which is why many patients spend years being doubted before diagnosis.
What treatments help with CRPS?
No single treatment suits everyone. The NHS says treatments can help manage symptoms, and Altru says earlier treatment tends to work better. A good plan is individual and starts with a clinician who has examined you.
What to do today
Start small. Write down your symptoms for one week: where the pain is, what sets it off, and any changes in color, temperature, swelling, or sweating. Bring that page to your next appointment and ask whether the standard diagnostic checklist has been applied. If you’d like to talk through your situation with us, schedule a free discovery call through our website, and we’ll tell you honestly whether our program fits.
