Complex Regional Pain Syndrome

Overview

Complex regional pain syndrome (CRPS) is a long-lasting pain condition that usually affects one arm, hand, leg or foot. It most often starts after an injury, an operation, or a period in a cast, but the pain is far stronger and lasts far longer than you would normally expect from the original injury. CRPS is not 'just in your head' — it is a real condition where the nerves, blood vessels, skin and muscles in the affected limb stop working together in the usual way. The affected limb may change colour, feel hot or cold, swell, become very sensitive to touch, and feel stiff or weak. The word 'complex' means it affects more than one body system, and 'regional' means it is limited to one area, usually a limb.

CRPS is uncommon, not rare. It is hard to count exactly, but studies suggest it affects a small number of people after injuries or operations — roughly a few people in every thousand after certain types of fracture. Because it is uncommon, some doctors may not see it often, which is one reason it can take time to be recognised.

CRPS can affect anyone at any age, including children and teenagers. It is most often seen in adults in mid-life and is more common in women than in men. The most commonly affected areas are a hand or wrist, or a foot or ankle. Children who develop CRPS tend to improve well with treatment, often faster than adults.

Symptoms

Common symptoms

• Pain that is burning, throbbing, stabbing or aching, and much stronger than expected for the original injury
• Pain that spreads beyond the area of the original injury, or keeps getting worse over weeks or months
• Extreme sensitivity to touch — even light touch, clothing or a breeze can hurt (doctors call this allodynia)
• Swelling in the affected limb, sometimes coming and going
• Skin that changes colour — red, purple, blotchy, pale or blue
• Skin that feels noticeably warmer or cooler than the other side
• Changes in sweating — the limb may be unusually sweaty or unusually dry
• Faster or slower hair and nail growth on the affected limb, or changes in skin texture
• Stiffness, weakness or tremor (shaking) in the limb
• A strange feeling that the limb does not quite belong to you, or that it feels 'odd' or 'foreign'
• Problems sleeping, and pain that is made worse by stress, cold or emotional upset
• Reduced ability to use the limb for everyday tasks like dressing, writing, walking or driving

Symptoms in children

• CRPS in children most often affects a leg or foot, though arms and hands are also common
• Children often describe the pain clearly but may show fewer visible changes like colour or swelling
• The limb may be held stiffly or avoided completely, and the child may stop taking part in sport or school activities
• Children may feel anxious or upset because the pain is not believed or is put down to 'growing pains'
• With early treatment, children and teenagers often recover well, and many improve fully

Symptoms in older adults

• CRPS can follow a fracture or an operation, such as wrist fracture or hip surgery, and may be mistaken for normal slow healing or arthritis
• Stiffness and weakness can make falls more likely, so balance and safety at home matter
• After a stroke, similar changes in a limb should always be checked by a doctor, because other conditions can look like CRPS
• Older adults may be taking several medicines for other conditions, so a careful review with a doctor or pharmacist is helpful

Causes

Main causes

• In most cases, CRPS follows an injury — a fracture, a sprain, a crush injury or a burn
• It can follow an operation or a period in a cast when a limb is not used for a while
• Sometimes it follows something as minor as a small knock, a blood test or an injection
• In some people there is no obvious trigger at all, which can be confusing and upsetting
• Doctors believe it involves changes in how nerves send pain signals, plus changes in blood flow, skin and the immune system in that area — not damage to the limb itself in the usual sense

Risk factors

• Having a fracture or operation, especially of the wrist, hand, ankle or foot
• Not moving a limb for a long period, such as while in a cast
• Being female — CRPS is more common in women
• Being an adult in mid-life, though any age can be affected
• Very severe pain soon after an injury, or pain that seems out of proportion to the injury
• High levels of stress or distress around the time of an injury
• Having had CRPS before — it can come back in the same limb or, less often, in another limb

When to see a doctor

See a doctor urgently if:

• You have severe pain that is far worse than your injury would explain, especially with colour, temperature or swelling changes
• Pain that is spreading or getting worse week by week despite rest and usual pain relief
• Signs of infection: spreading redness, warmth, pus, or feeling feverish
• A new wound, blister or ulcer on the affected limb
• The limb becomes cold, pale or blue and feels numb
• You are unable to use the limb at all for everyday tasks

Book a routine appointment if:

• You have ongoing pain, stiffness, swelling or sensitivity in one limb after an injury or operation that is not settling as expected
• You notice changes in skin colour, sweating, hair or nail growth on one limb
• The pain is affecting your sleep, mood, work or studies
• You would like to discuss treatment options or ask for a referral to a specialist pain service
• You feel your symptoms are not being taken seriously — it is always reasonable to ask for a second opinion

Diagnosis

There is no single test for CRPS. A doctor — often a GP first, then a pain specialist or neurologist — makes the diagnosis by listening to your story, examining the limb, and comparing it with the other side. They will look for a pattern: pain that does not match the original injury, plus changes in skin colour, temperature, sweating, swelling, movement or sensation. Doctors use agreed international criteria to help, which require you to have ongoing pain out of proportion to any injury, along with changes in at least a few areas such as sensation, blood flow, sweating or movement. Importantly, the diagnosis is based on your symptoms and examination, not on a scan.

Tests that may be done

• A full examination of both limbs, comparing colour, temperature, swelling, sensation, strength and movement
• Blood tests to look for other causes of pain or swelling, such as infection or inflammation
• X-rays or other imaging, mainly to check on the original injury or rule out other problems
• Sometimes a bone scan or MRI, though these are not needed to diagnose CRPS itself
• Sometimes nerve tests to check that the nerves themselves are working normally
• A review of your medicines and history by your GP or pharmacist to rule out other explanations

What to expect at your appointment

Getting a diagnosis can take time, and that can be frustrating. Some people are told at first that nothing is wrong because tests come back normal — but normal tests do not mean your pain is not real. If CRPS is suspected, ask your GP about referral to a specialist pain clinic. Bring a simple diary of your symptoms, what makes them better or worse, and photos of any colour changes, as this can really help. A diagnosis is usually made over one or more appointments rather than in a single visit.

Treatment

Treatment works best when it starts early and involves a team — usually your GP, a physiotherapist or occupational therapist, and a specialist pain service. The aim is not to 'cure' CRPS overnight, but to reduce pain, keep the limb moving, protect your function and help you get back to everyday life. Different treatments suit different people, and it often takes a combination of approaches rather than one single answer. Your goals and preferences should be central to the plan.

Self-care at home

• Keep gently moving the limb — even small, gentle movements several times a day are better than resting it completely, which can make stiffness worse
• Try 'desensitisation': gently touching the limb with different textures (cotton, soft brush, dry flannel) for short periods, building up slowly over weeks
• Use warm or cool packs for comfort, always wrapped in a cloth, and check the skin afterwards — never apply strong heat or ice directly to numb or sensitive skin
• Pace yourself: alternate activity with rest rather than doing everything on a good day and paying for it later
• Keep a simple diary of pain, triggers and what helps, to share with your clinician
• Ask about hand or foot therapy, splints or supports — but only ones recommended by a therapist, as the wrong support can increase stiffness
• Protect the limb from knocks and extreme temperatures, and keep skin clean and moisturised to avoid cracks and sores
• Learn relaxation or breathing techniques — stress and pain feed each other, and calming the nervous system can genuinely help

Medical treatments

Treatment is tailored to you and usually combines several approaches. Physical and occupational therapy is the cornerstone — it focuses on graded movement, strength, desensitisation and practical ways to manage daily tasks. Your doctor may discuss medicines used for nerve-type pain; these are always started at a low level and reviewed regularly, and your GP or pharmacist can explain benefits and side effects. Specialist pain clinics may offer nerve blocks (injections that temporarily calm nerve signals), sympathetic nerve blocks, or specialised programmes combining physical therapy with psychological support such as cognitive behavioural therapy, which helps people cope with long-term pain and is not a suggestion that the pain is imaginary. For people with severe, persistent symptoms, specialists may discuss advanced options such as nerve stimulation devices. All of these are decisions to make together with your healthcare team, taking account of your symptoms, other conditions and preferences.

When is surgery considered?

Surgery is not usually used to treat CRPS itself. Occasionally, specialist teams may discuss procedures such as implanted nerve stimulation devices or other advanced pain treatments for people whose symptoms are severe and have not responded to other approaches. These are only offered after careful assessment by a specialist pain service, and they are not suitable for everyone.

Living with this condition

CRPS can make ordinary things — dressing, cooking, walking, typing, sleeping — harder and more tiring. It helps to break tasks into smaller steps, plan rest breaks, and use aids and gadgets where they make life easier (your occupational therapist can advise). Keep the limb gently active rather than protecting it completely. Sleep matters too, so try a regular wind-down routine and a comfortable position that does not put pressure on the sensitive limb. Many people find it helpful to keep a note of what helps on good and bad days, and to share that with family and employers so they understand.

Lifestyle tips

• Stay gently active overall — walking, swimming or other movement you can tolerate helps circulation, mood and sleep
• Avoid smoking, which narrows blood vessels and can worsen circulation problems
• Keep warm in cold weather — gloves, warm socks and layers can reduce pain flares
• Manage stress where you can: relaxation, breathing exercises, hobbies and time with people you enjoy all help
• Pace your activity and build rest into your day rather than pushing through pain
• Protect the limb from knocks, and take care with hot water bottles, radiators and sharp objects if sensation is reduced
• Keep up with work or studies where possible, with adjustments — your GP or occupational health service can support this

Diet and exercise

There is no special diet that treats CRPS, but eating regularly and well supports energy, mood and healing. Aim for a balanced pattern of meals with plenty of vegetables and fruit, some protein and whole grains, and drink enough water. Gentle, regular movement is one of the most helpful things you can do. A physiotherapist can help you build a graded programme — starting small, such as a few minutes of gentle movement or a short walk, and increasing only when you feel ready. The aim is steady progress without flare-ups, not pushing through severe pain.

Mental health and emotional wellbeing

Living with constant pain is genuinely hard, and it is very common to feel low, anxious, frustrated or exhausted. Those feelings are a normal response to a difficult situation, not a sign of weakness, and they are not 'causing' your CRPS. Talking about how you feel helps — with friends, your GP, or a counsellor or psychologist familiar with long-term pain. If you ever feel you cannot cope or have thoughts of harming yourself, please reach out immediately to your local emergency number or a crisis support line in your country, or contact a trusted person and ask them to stay with you. You deserve support, and help is available.

Prevention

CRPS cannot be completely prevented, and it is not your fault if it happens. However, some general steps may help: getting prompt treatment for injuries, avoiding long periods of complete immobilisation where your clinician advises it is safe to move, and speaking up early if pain after an injury seems far worse than expected. If you have had CRPS before and are facing surgery or an injury, tell your healthcare team — they can watch for early signs and act quickly. Ask your doctor whether there is anything specific you can do in your situation.

Screening programmes

There is no screening test for CRPS. The best 'screening' is awareness: if pain after an injury or operation is much stronger, longer-lasting or different from what you expected, get it checked early.

Complications

If left untreated

• Stiffness and loss of movement in the limb, which can become harder to reverse over time
• Muscle weakness and wasting from not using the limb
• Spread of pain to a wider area, or occasionally to another limb
• Skin changes, and in some cases small wounds or ulcers that are slow to heal
• Sleep problems and persistent tiredness
• Low mood, anxiety and frustration, which can in turn make pain feel worse
• Difficulties with work, study, driving, caring responsibilities and finances
• Strain on relationships and family life

Long-term outlook

The outlook varies from person to person. Many people improve, especially when treatment starts early, and children and teenagers often recover particularly well. Some people continue to have symptoms long-term, but even then, the right combination of therapy, pain management and support can make a real difference to daily life. CRPS is a condition people learn to manage rather than a life sentence, and there is good reason to feel hopeful. Working closely with a team you trust, setting small realistic goals, and asking for help when you need it are all steps that tend to lead to better outcomes.

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