Complex regional pain syndrome (CRPS)

What CRPS is

Complex regional pain syndrome is a condition where pain carries on long after an injury should have healed, and is much worse than expected. It usually affects one arm, hand, leg or foot.

It most often starts after an injury such as a broken wrist, a sprain or an operation, usually within a month. In about 9 in 100 people there is no clear injury first. Nobody fully understands why it happens. It seems the nerves, immune system and brain react abnormally to the injury and keep sending pain signals.

CRPS is uncommon and is often missed or diagnosed late. It can affect anyone, at any age, but it is more common in women than men.

The good news is that most people get better. UK guidelines say about 8 in 10 people find their pain goes or improves, though many are left with some milder pain or stiffness. About 15 in 100 still have long-term symptoms after 2 years.

Types of CRPS

Doctors describe CRPS in a few ways. The type doesn't usually change your treatment, but it can help you understand letters from specialists.

CRPS type 1

By far the most common type. It happens without a major nerve injury, often after a fracture, sprain or surgery. It used to be called reflex sympathetic dystrophy (RSD).

CRPS type 2

Happens after a clear injury to a major nerve. It used to be called causalgia. It is treated in the same way as type 1.

Warm CRPS

The limb is hot, red and swollen. This is more common early on and looks like inflammation.

Cold CRPS

The limb is cold, pale or bluish and may be sweaty. It is more common in long-lasting CRPS and can be harder to treat.

CRPS not otherwise specified

Used when someone has CRPS but doesn't quite meet all the diagnostic criteria, and nothing else explains their symptoms.

Spread

In some people the pain spreads beyond the first area, for example up the limb or, less often, to another limb.

Symptoms and how it changes

The main symptom is pain that can be burning, stabbing or stinging, and is often there all the time. Other common symptoms include:

First weeks

Early CRPS

Pain is out of proportion to the injury. The limb is often warm, red and swollen. This is when treatment works best.
After 4 weeks

Check point

If symptoms aren't improving with treatment, UK guidelines say you should be referred to a specialist.
Months

Improving or settling

Most people slowly improve. Some have flare-ups lasting days or weeks, often after stress or a knock.
Over 2 years

Long-term CRPS

A smaller group still has symptoms. The limb may be colder and stiffer. Specialist rehabilitation can still help.

Timings are a rough guide. Everyone's CRPS is different.

When to get urgent help

Call 999 or go to A&E if

your limb is suddenly very swollen, pale or cold after a cast or splint is put on
a limb in a cast becomes extremely painful, numb or you can't move your fingers or toes
you have chest pain or sudden breathlessness
you have thoughts of ending your life and feel you may act on them

Call NHS 111 if

the skin on the limb breaks down, or looks infected (hot, weeping, spreading redness)
you have a high temperature with a painful, swollen limb
you are in a mental health crisis. In England, call 111 and choose the mental health option (option 2)

See your GP soon if

pain after an injury is much worse than expected or isn't easing
the limb changes colour, temperature or swells
you can't bear anything touching the skin
your symptoms have spread or are getting worse

CRPS pain can be overwhelming. If you are struggling, you can talk to Samaritans any time, day or night, free on 116 123.

Diagnosis and referral

There is no single test for CRPS. Doctors use a checklist called the Budapest criteria. It looks at four groups of signs and symptoms: changes in feeling, skin colour and temperature, swelling and sweating, and movement, skin, hair or nails. You need ongoing pain that is out of proportion to the injury, enough signs and symptoms across these groups, and no other condition that explains them better.

Blood tests, X-rays or scans may be done to rule out other causes, such as infection, a blood clot or a fracture that hasn't healed.

Your GP, A&E or fracture clinic may make the first diagnosis. UK guidelines say you should be referred to a specialist pain service if your pain is severe, you are very distressed or disabled by it, or you aren't improving after 4 weeks of treatment. A referral is also needed if you develop muscle spasms or skin ulcers, or if the diagnosis isn't clear.

Ask early

Early treatment gives the best chance of recovery. If you think you have CRPS, say so and ask your GP to check the Budapest criteria. The CRPS Network has a free tool, CRPSAssist, for doctors who don't see CRPS often.

Treatments and medicines

The main aim is to get the limb moving and to calm the over-sensitive nervous system. Treatment usually combines four things: education, physical rehabilitation, pain relief and psychological support.

Physiotherapy and occupational therapy

GP, hospital or pain clinic referral

The most important treatment, ideally started early. Gentle exercise, hydrotherapy, and help to use the limb in everyday tasks. Progress is usually measured over weeks to months.

Desensitisation

Taught by a physiotherapist or occupational therapist

Gently touching the skin with different textures, little by little, so the limb gets used to touch again.

Mirror therapy and graded motor imagery

Specialist physiotherapy

Using a mirror, pictures and imagined movement to help the brain "re-map" the painful limb. Usually done in stages over several weeks.

Simple painkillers

Pharmacy or prescription

Paracetamol or anti-inflammatories such as ibuprofen may help with pain from the original injury, but are unlikely to ease CRPS pain itself.

Nerve pain medicines

Prescription

Tricyclic antidepressants (amitriptyline or nortriptyline) and anticonvulsants (gabapentin or pregabalin). They can help nerve pain and sleep. They are started low and increased slowly, so it can take several weeks to know if they work. They must be reduced gradually, not stopped suddenly.

Bisphosphonates

Specialist only

UK guidelines say a specialist may consider a one-off drip of pamidronate for CRPS that started less than 6 months ago.

Psychological support

Pain clinic or NHS Talking Therapies

CBT and similar therapies help you manage pain, fear of movement, low mood and sleep. CRPS is not caused by your mind, but living with it is hard.

Opioids don't work well for CRPS

The NHS says opioids such as codeine and morphine are not very effective for CRPS. Long-term use can cause dependence and other problems. UK guidelines also advise against a type of nerve block using guanethidine, as trials showed no benefit. Talk to your doctor before changing any medicine.

CRPS is managed using its own UK guidelines from the Royal College of Physicians. This means some nerve pain medicines that NICE advises against for other long-term pain, such as fibromyalgia, may still be offered for CRPS.

Specialist options

Pain clinic

If not improving after 4 weeks

A team of doctors, physiotherapists, occupational therapists and psychologists. They can review medicines and plan your rehabilitation.
CRPS specialist centres

GP or pain consultant referral only

Centres with a special interest in CRPS include the Royal United Hospital in Bath, INPUT at St Thomas' and UCLH in London, The Walton Centre in Liverpool, the Royal National Orthopaedic Hospital in Stanmore, and services in Leeds, Manchester, Oxford, Cambridge, Cardiff, Glasgow and Craigavon. Some offer intensive residential programmes.
Pain management programme

Group sessions over several weeks

Aims to improve daily life rather than remove all pain. Covers pacing, movement, relaxation and coping with flare-ups.
Spinal cord stimulation

After about 6 months of other treatment

A small implanted device sends mild electrical pulses to the spinal cord to change pain signals. It is only considered when other treatments haven't helped, and after a successful trial.

Self-help and living well

Your limb

Keep using and moving it gently, little and often
Do your desensitisation and exercises every day
Protect it from knocks and extreme temperatures
Check the skin daily for cuts or sores

Your day and mind

Pace activities to avoid boom and bust
Keep a regular sleep routine
Learn relaxation or breathing techniques for flare-ups
Talk to others with CRPS through a support group

Getting the best care

Tips for appointments

Take photos of your limb on bad days to show colour and swelling changes
Keep a short diary of pain, sleep and what you can and can't do
Ask: "Could this be CRPS? Have you checked the Budapest criteria?"
Ask for early physiotherapy from someone who knows CRPS
If you aren't improving after 4 weeks, ask for a pain clinic referral
Bring someone with you to help remember and to speak up for you
You can ask for a second opinion or referral to a CRPS specialist centre

CRPS and work

CRPS can count as a disability under the Equality Act 2010 (the Disability Discrimination Act in Northern Ireland). This applies if it has more than a minor effect on your daily life and has lasted, or is likely to last, at least 12 months. The law looks at how you would be without treatment.

If so, your employer must make reasonable adjustments. These might include:

Changing tasks that use the affected limb
Working from home to avoid a painful commute
Flexible hours around rehabilitation
A phased return to work
A desk away from draughts and cold air
Parking near the entrance
Time off for appointments
Extra breaks to rest or move

Equipment can help a lot. Examples include one-handed or ergonomic keyboards, a vertical or trackball mouse, voice recognition software, forearm supports, a sit-stand desk, a footrest, and a supportive chair.

Access to Work is a government grant that can pay for equipment, support and travel to work. For advice on your rights, contact Acas or Citizens Advice.

Benefits

If you can't work, you may get Statutory Sick Pay from your employer for up to 28 weeks. You may also be able to get Personal Independence Payment (PIP), or Adult Disability Payment in Scotland, whether or not you work. Universal Credit or Employment and Support Allowance may also help. Turn2us and Citizens Advice can help you check.

How The Beyond Pain Foundation can help

Early treatment matters with CRPS. If NHS waits are too long, or the help you need isn't available to you on the NHS, we may be able to fund:

A private consultation with a pain specialist who knows CRPS
Specialist physiotherapy or hand therapy, including graded motor imagery
Hydrotherapy sessions
An occupational therapy assessment for work or home
Travel to a CRPS specialist centre
Equipment such as ergonomic keyboards, voice software, a sit-stand desk or daily living aids

We fund treatment and equipment, not everyday living costs such as rent or bills. Treatment must be from a registered or qualified practitioner. Prices vary, so always get a written quote to include with your application.

Apply for funding Check the requirements

Support and sources

Burning Nights CRPS Support

Charity, helpline and support groups

Helpline 01663 795055, email and live chat. Online and local support groups, befriending and counselling.

burningnightscrps.org

The CRPS Network

Health professionals and researchers

Information for patients, the UK diagnosis and treatment guidelines, and a list of CRPS specialist services.

crps.org.uk

NHS

Health information

Symptoms, diagnosis and treatment of CRPS.

nhs.uk/conditions/complex-regional-pain-syndrome

Sources for this guide

Last reviewed: October 2026.