The pain is out of proportion to the apparent injury. That is the diagnosis, not an exaggeration. That is why most patients are not believed, and it is the inherent nature of neuropathic injury.

COMPLEX REGIONAL PAIN SYNDROME

The pain is out of all proportion to the injury, the limb looks and feels wrong, and somebody has probably implied you are exaggerating. You are not. This is a recognized condition with diagnostic criteria, and the criteria are what nobody applied.

The disproportion is the disease, not a red flag about you

This is the central fact and almost everything that goes wrong for these patients follows from it. In CRPS the pain is enormously out of proportion to the observed tissue damage — and observed is the operative word, because the tissue damage is frequently minor, healed, or was never impressive to begin with.

A clinician trained to expect pain to track injury looks at a healed wrist fracture, a well-performed release, or a scan showing nothing, and concludes that the reported pain cannot be coming from there. The reasoning is sound and the premise is wrong. The pain is not coming from the tissue. It is coming from a nervous system that has changed how it processes signals from that limb.

Phantom limb is the clearest way to understand it

After an amputation a substantial proportion of people experience severe pain in a limb that is no longer there. There is no tissue at all to be damaged, and the pain is real, severe and neuropathic.

Nobody accuses those patients of exaggerating, because the absence of the limb makes the point unarguable: pain is generated by the nervous system, and it does not require ongoing tissue damage to be produced or to be severe.

CRPS is the same principle with the limb still attached — which is precisely why it is disbelieved. The limb is there, it looks broadly intact, and the mismatch between how it looks and how it feels gets read as a problem with the patient rather than as the defining feature of the diagnosis.

What that means for how you are treated

It means the search for more tissue damage is usually futile. Repeat imaging, repeat scoping, another opinion on the original injury — all of it looks for something that is not the problem, and each normal result is quietly filed as further evidence against you.

It also means the diagnosis is made by examining the limb for the signs listed below rather than by finding a lesion. That is not a weaker kind of diagnosis. It is the correct one for a condition of the nervous system.

What people are told, and what is actually happening

A wrist fracture that healed. A carpal tunnel release that went technically well. A minor injury months ago. And a limb that is now burning, swollen, exquisitely sensitive to touch, and changing color and temperature in a way nobody can explain.

At that point the file starts describing somebody whose symptoms exceed the findings, because the findings were never looked for. CRPS is diagnosed on a defined pattern of sensory, vasomotor, sudomotor and motor signs — not on imaging, which is normal, and not on bloods, which are normal.

The Budapest criteria, in plain terms

The internationally used criteria require continuing pain disproportionate to the inciting event, plus symptoms and observed signs across four categories.

• Sensory — hypersensitivity to light touch, or pain from things that should not hurt. A sleeve, a breeze, water in the shower.
• Vasomotor — the limb changes color, or one side is measurably warmer or cooler than the other.
• Sudomotor / edema — swelling, or sweating that differs between sides.
• Motor / trophic — reduced range, weakness, tremor, and changes in hair, nail or skin growth.

The distinction that matters diagnostically: symptoms are what you report, signs are what a clinician observes at the visit. You need both, in enough categories. That is why an appointment where nobody looked at the limb properly cannot exclude this.

Why it is missed in a neck and arm practice

Because it looks like something else first. Early CRPS after a hand or wrist procedure gets attributed to the operation not having worked. Burning arm pain gets called radiculopathy. Hypersensitivity gets called a difficult patient.

And because it sits in exactly the population an upper-limb practice sees: people after a fracture, a release, a fusion, or an injury that seemed minor. Asking the four questions above takes two minutes and is the whole difference.

The evidence position, stated honestly

This is where most pages about CRPS become unreliable, so here is the uncomfortable version. A Cochrane review of interventions for CRPS concluded that the certainty of evidence across most treatments is low or very low. That is not a reason to do nothing. It is a reason to be suspicious of anybody offering you a confident protocol.

What the guidelines do consistently support is early, graded restoration of function — movement, desensitization, mirror therapy, graded motor imagery — with interventional treatment used to make that function possible rather than as a treatment in itself. The rehabilitation is the treatment; the injections buy a window in which it can happen.

What we do here

Establish the diagnosis properly against the criteria, including examining the limb for signs rather than taking a history and ordering a scan. Exclude the things that mimic it — an untreated nerve compression, an infection, a vascular problem, an inflammatory arthropathy.

Then treat to enable function. A stellate ganglion block is the usual first interventional step for an upper limb, and where the condition is established and refractory, dorsal column stimulation is a considered option rather than a first move.

The thing that changes the outcome most

Time to diagnosis. CRPS treated early, with the limb kept moving, does substantially better than CRPS that has spent a year being disbelieved while the limb was protected and stopped being used.

That is the strongest argument on this page for getting it named. Not because naming it is treatment, but because the protective disuse that follows being disbelieved is itself part of what entrenches the condition.

Warm and cold, and why the limb changes

Early CRPS is often the warm, red, swollen version — the limb looks inflamed and feels hot. Later it more often becomes the cold, mottled, sweaty version with hair and nail changes. Both are the same condition at different points, and people are frequently told the second one cannot be CRPS because it does not look inflamed.

The temperature difference between sides is a sign worth measuring rather than estimating, and it is one of the four categories the criteria ask about.

What makes it worse, reliably

• Immobilizing the limb. Slings, splints and protective disuse entrench it. This is the single most damaging piece of well-meant advice people receive.
• Repeated procedures aimed at the original injury, when the original injury has healed and the problem is now the nervous system.
• Being disbelieved, which reliably produces more guarding and less movement.
• Untreated sleep loss, which lowers pain thresholds and is almost universal here.

What the plan looks like

Restoration of movement from the first week, graded and often uncomfortable, with desensitization work and mirror therapy or graded motor imagery where indicated. Interventional treatment exists to make that possible on days when it otherwise would not be.

Medication is adjunctive rather than central. And the metabolic terrain matters here as it does everywhere on this site — a nervous system trying to normalize in the presence of insulin resistance and chronic inflammation is working uphill.

What people ask about CRPS

Is there a test that proves it?

No, and that is a feature of the condition rather than a gap in your workup. It is a clinical diagnosis made against defined criteria, which is why the examination of the limb matters more than any scan. What the stellate ganglion block treats.

Does it spread?

It can involve other limbs in a minority of people. That is not inevitable and it is not a reason to stop using the affected one — disuse is a bigger risk than spread. When the hands are the problem.

Will it go away?

Many cases improve substantially, particularly those treated early with a focus on restoring function. A proportion become long-standing. Anybody offering certainty in either direction is not being straight with you. Where spinal cord stimulation fits.

Is it psychological?

No. It is a disorder of the nervous system with observable physical signs. Being disbelieved for a year is psychologically damaging, which is a different statement and a common one. What the stellate ganglion block treats.

Related reading

• Stellate ganglion block
• Dorsal column stimulation
• When your hands are the problem
• Carpal tunnel hydrodissection
• EMG and nerve conduction studies
• Cervical radiculopathy