Complex regional pain syndrome (CRPS) is a poorly understood condition in which a person experiences persistent severe and debilitating pain.

Although most cases of CRPS are triggered by an injury, the resulting pain is much more severe and long-lasting than normal.

The pain is usually confined to one limb, but it can sometimes spread to other parts of the body.

The skin of the affected body part can become so sensitive that just a slight touch, bump or even a change in temperature can provoke intense pain.

Affected areas can also become swollen, stiff or undergo fluctuating changes in colour or temperature.

Many cases of CRPS gradually improve to some degree over time, or get completely better. However, some cases of CRPS never go away, and the affected person will experience pain for many years.


When to seek medical advice

You should see your GP if you have persistent pain that is preventing you from carrying out everyday activities.

CRPS can be difficult to diagnose because it involves a number of tests to rule out other possible causes. It's therefore best to seek help as soon as possible, because treatment may reduce unnecessary suffering, if started early.


What causes CRPS?

The cause of CRPS is unknown, but it's generally thought to be the result of the body reacting abnormally to an injury.

It used to be thought that CRPS was a psychosomatic condition (the symptoms were "all in the mind"), but research has since disproved this.


Who is affected

It's difficult to estimate exactly how common CRPS is, as many cases may go undiagnosed or misdiagnosed. A study claimed that up to 1 in 3,800 people in the UK develop CRPS each year.

CRPS can begin at any age, including in children, although the average age for symptoms to start is around 50. Women make up around 3 out of every 4 cases.

How CRPS is treated

Treatment for CRPS involves 4 main aspects:

education and self-management – being given clear information about your condition and advice on any steps you can take to help manage your condition yourself

physical rehabilitation – treatment to help manage your symptoms and reduce the risk of long-term physical problems, such as physiotherapy exercises

pain relief – treatments to help reduce your pain, such as anticonvulsants or antidepressants

psychological support – interventions to help you cope with the emotional impact of living with CRPS, such as cognitive behavioural therapy (CBT)

Due to the complex nature of CRPS, a number of different professionals will usually be involved in your care.

The pain associated with CRPS is usually confined to one limb 

Pain forum

Pain may think it had the upper hand but buy a yo…

2 replies

So good to find other people who are suffering with similar problems. I have…

2 replies

Hi Blokie ,how are you doing are you still on Tramodol if so what dose do you…

7 replies

I saw an orthopedist today and it turns out that the lump in my hands (they…

1 reply

My partner was diagnosed with herniated disc about 3 years ago. It is so bad…

6 replies

More from the community

Symptoms of complex regional pain syndrome 

The main symptom of complex regional pain syndrome (CRPS) is severe, continuous and debilitating pain. It is usually confined to one limb, but can spread to other parts of the body in some cases.

Chronic pain

The pain associated with CRPS is usually triggered by an injury, but is a lot more severe and long-lasting than you would normally expect.

The pain is usually burning, stabbing or stinging, but there may also be a tingling sensation and numbness.

You may have periods of pain lasting a few days or weeks, called flare-ups, where the discomfort gets worse. Stress in particular can lead to flare-ups, which is why relaxation techniques are an important part of treating CRPS.

If you have CRPS, your skin in the affected area can become very sensitive, and even the slightest touch, bump or change in temperature can provoke intense pain.

You may hear this described in the following medical terms:

hyperalgesia – extreme sensitivity to pain

allodynia – experiencing pain from something that should not be painful at all, such as a very light touch

Other symptoms

In addition to chronic pain, CRPS can also cause a range of other symptoms, including:

strange sensations in the affected limb – it may feel as if the affected limb does not belong to the rest of your body, or it may feel bigger or smaller than the opposite, unaffected limb

alternating changes to your skin – sometimes your skin may be hot, red and dry, whereas other times it may be cold, blue and sweaty

hair and nail changes – your hair and nails may grow unusually slowly or quickly, and your nails may become brittle or grooved

joint stiffness and swelling (oedema)

tremors and muscle spasms (dystonia)

difficulty moving the affected body part

difficulty sleeping (insomnia)

small patches of fragile bones (osteoporosis) in the affected limb – although there is no evidence this could lead to fractures

Some of these problems can make it very difficult for people with CRPS to move around or travel easily.

Further problems

The emotional strain of living with chronic pain can sometimes lead to psychological problems, such as depression and anxiety. During periods of extreme pain, some people may even consider suicide.

See your GP as soon as possible if you have been experiencing feelings of depression or suicide. They will be able to provide help and support. Alternatively, you can call the Samaritans on 08457 90 90 90. They are available 24 hours a day to talk through any issues that you may be experiencing, and will do so in total confidence.

In very rare cases, CRPS can also lead to further physical complications, such as skin infections and ulcers (open sores), muscle atrophy (where the muscles begin to waste away) and muscle contractures (where the muscles shorten and lose their normal range of movement).

When to see your GP

You should see your GP if you have persistent pain that is preventing you from carrying out everyday activities.

CRPS can be difficult to diagnose, and it's best to seek help as soon as possible, because early can help reduce any unnecessary suffering.


Causes of complex regional pain syndrome 

Although complex regional pain syndrome (CRPS) has been a recognised medical condition for more than 150 years, its exact cause is still unclear.

Previous injury

The condition usually seems to develop within a month of an injury, either minor or more serious. These can include:

bone fractures

sprains and strains



Most people will recover from these injuries without experiencing any significant long-term effects, but people with CPRS develop pain that is much more severe and long-lasting than usual.

The pain can spread beyond the site of the original injury, usually affecting an entire limb. For example, CRPS may affect your whole arm after an injury to your finger or hand. In some cases, more than one area of the body can be affected.

CRPS has also been known to occur after surgery to a limb or after part of a limb has been immobilised (for example, in a plaster cast).

Why does CRPS develop after an injury?

It is not known why some people develop CRPS after an injury. Due to the complex nature of the symptoms, it is unlikely the condition has a single, simple cause.

Some people even believe CRPS shouldn't be regarded as a single medical condition, because the symptoms could be the result of several different ones.

One of the main theories suggests that CRPS is the result of a widespread abnormal response to an injury that causes several of the body's systems to malfunction, including:

the central nervous system – the brain and spinal cord

the peripheral nervous system – the nerves that lie outside the central nervous system

the immune system – the body's natural defence against illness and infection

the blood vessels – the series of arteries and veins that transport blood around the body

These systems are responsible for many body functions that are often affected in people with CRPS, such as detecting pain and transmitting pain signals, triggering inflammation (swelling), and controlling temperature and movement.

It has also been suggested that some people may be more susceptible to CRPS because of genetic factors, although this is not clear and it is very unlikely other members of your family will be affected if you have CRPS.

In the past, some people believed CRPS may be a psychological condition that makes people think they are experiencing pain. However, this theory has been largely discredited.

Diagnosing complex regional pain syndrome 

There is no single test for complex regional pain syndrome (CRPS). It is usually diagnosed by ruling out other conditions that have similar symptoms.

As a result, it can take a long time for a confident diagnosis of CRPS to be made. It's estimated that the average length of time between the start of symptoms and a diagnosis is up to two years.


Some of the tests you may have to rule out other conditions can include:

blood tests – to rule out an underlying infection or rheumatoid arthritis

a magnetic resonance imaging (MRI) scan – to rule out underlying problems with your tissue or bones

an X-ray – to rule out problems with the joints and bones

nerve conduction studies – to rule out damage to nerves

A physical examination may also be carried out by your GP or another specialist to check for physical signs of CRPS, such as swelling and changes to your skin’s temperature and appearance.

A diagnosis of CRPS can usually be made if you have clear symptoms of the condition and no other possible cause can be found.


If you are diagnosed with CRPS, you will usually be referred to a local specialist pain clinic. These are mostly located within hospitals.

Referrals are ideally made as soon as possible to ensure treatment can be started quickly, because treatment can often improve functionality of the limb and may improve pain levels.

Treating complex regional pain syndrome 

There is no known cure for complex regional pain syndrome (CRPS), but a combination of physical treatments, medication and psychological support can help manage the symptoms.

It's estimated that around 85% of people with CRPS will slowly experience a reduction in some of their symptoms, including pain, over the first two years after the condition starts. However, some people will experience continuous pain despite treatment and, in rare cases, may develop further problems, such as muscle wastage.

There is currently no way to predict which cases will improve and when this may happen.

Your treatment plan

Treatment for CRPS involves four main areas:

education and self-management – advice about any steps you can take to help manage the condition

physical rehabilitation – to help manage symptoms and reduce the risk of long-term physical problems

pain relief – treatments to help reduce your pain

psychological support – interventions to help you cope with the emotional impact of living with CRPS

Some of the main treatments used are described below.


As part of your treatment, you will be advised about things you can do yourself to help control your condition.

This may include:

being encouraged to stay as active as possible and not avoid using the affected body part

learning relaxation techniques and methods to help improve your quality of sleep

being advised about pacing yourself (balancing periods of activity with periods of rest)

continuing rehabilitation treatments at home, such as desensitisation techniques (see below)

accessing any support groups in your local area


Physical rehabilitation

Physical rehabilitation involves a number of different treatments that are designed to help you manage your symptoms and prevent physical problems, such as muscle wastage and bone contortions.

Some of the techniques that may be used as part of your physical rehabilitation programme are described below.


A physiotherapist can help devise a suitable exercise plan involving a range of exercises designed to gradually improve the strength and flexibility of the affected body part. 

Your exercise plan may include a range of exercises, from simple stretches to exercises in water (hydrotherapy) or weight-bearing exercises.

These exercises can be very painful at first, but research has shown that pain can improve significantly in people who persist with the treatment – although this does not always happen. Regular exercises can also reduce the severity of physical problems associated with immobility, such as muscle wastage.


Desensitisation is a technique used to reduce the sensitivity of body parts affected by CRPS.

It usually involves touching an unaffected body part with materials of different textures, such as wool and silk, and concentrating on how this feels. The same materials are then applied to the painful, affected body part while trying to recall what it felt like when you were touching the unaffected body part.

This process is likely to be uncomfortable or painful at first, but it may eventually reduce the sensitivity in the affected body part so it is more similar to unaffected areas.

Mirror visual feedback and graded motor imagery

Mirror visual feedback and graded motor imagery are two techniques that aim to "trick" the brain into thinking that areas of the body affected by CRPS are no longer affected.

These techniques involve carrying out exercises with a mirror positioned so you see a reflection of the unaffected limb where you would normally see the affected limb.

Pain relief

There are several medicines that may help to treat CRPS, which your pain specialist will be able to discuss with you.

Your treatment team will try lower-strength painkillers first, and will only use stronger painkillers if necessary.

None of the medicines used to treat people with CRPS are licensed for this use in the UK. This means these medicines may not have undergone clinical trials to see if they are effective and safe in treating CRPS specifically.

However, they will have a licence to treat another condition and will have undergone clinical trials for this. Doctors may choose to use an unlicensed medication if they are thought to be effective and the benefits of treatment outweigh any risks.

Some of the main pain relief treatments are discussed below.

Non-steroidal anti-inflammatory drugs (NSAIDs)

The first painkillers often used to treat CRPS are over-the-counter painkillers called non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.

These medications can help reduce the pain caused by the injury that triggered CRPS. They can also treat CRPS-associated pains, such as muscle pain in the shoulder when the CRPS is in the hand. However, NSAIDs are unlikely to directly reduce CRPS pain. 


Anticonvulsants are usually used to treat epilepsy, but they have also been found to be useful for treating nerve pain. Gabapentin and pregabalin are the most widely used anticonvulsants for treating CRPS.

Common side effects of these medications include drowsiness and dizziness. There is a small increased risk of suicidal thoughts, which may be seen as early as a week after starting treatment.

You should avoid suddenly stopping treatment with these medications, because you may experience withdrawal symptoms. If you feel you no longer need to take it, your GP will arrange for your dose to be slowly reduced over a period of at least a week.

Tricyclic antidepressants

Tricyclic antidepressants (TCAs) were originally designed to treat depression, but like anticonvulsants were found to be effective in treating nerve pain. Amitriptyline and nortriptyline are the most widely used TCAs for treating CRPS, although nortriptyline generally has fewer side effects.

These medications can often improve sleep, and are generally taken in the early evening, to reduce the risk of "hangover" effects the next morning.

Possible side effects include dry mouth, blurred vision, constipation, heart palpitations and difficulty urinating.

You may experience withdrawal effects if you stop taking these medications suddenly. If you feel you no longer need to take TCAs, your GP will arrange for your dose to be slowly reduced over a period of at least four weeks. 


If you are experiencing severe pain, opiates such as codeine and morphine can provide pain relief.

Common side effects of opiate painkillers include nausea and vomiting, constipation, dry mouth, tiredness and cognitive problems (thinking processes can be slower). Long-term use of high doses has been linked to more serious problems, such as absent periods in women, absent periods, depression, and erectile dysfunction in men.

There are circumstances where the benefits of using opiates outweigh the associated risks, but unfortunately these medications are often not very effective in CRPS. Long-term use of high doses is generally not recommended, although exceptions may be made in a very small number of cases.

You may worry that you could become addicted to opiates or other pain medications, but genuine addiction (taking a medication despite knowing it is harmful) is rare. However, there is a risk you may become "dependent" on opioids, which means your body and mind do not want to stop taking them, even if they are not very effective, and you may feel worse for a limited period of time when you do reduce or stop taking them.

Spinal cord stimulation

If medication does not lessen your pain, a treatment called spinal cord stimulation may be recommended.

This involves having a device placed under the skin of your tummy or buttocks. This device produces mild electrical pulses that are sent to your spinal cord.

These pulses cause changes to how you feel pain. You should feel a tingling sensation in the part of your body that usually hurts, which masks the pain. The level of stimulation can be adjusted as your pain improves or gets worse, and the device can be removed if necessary.

The National Institute for Health and Care Excellence (NICE) states that spinal cord stimulation should only be considered if:

you are still experiencing pain after six months of trying other treatments

you have had a successful trial of the stimulation

Your care team will discuss spinal cord stimulation with you if they think it could help.

Psychological support

Living with a long-term, painful condition can be distressing, and people with  may experience psychological problems, such as anxiety and depression.

It's important to look after your psychological wellbeing, because feelings of depression and anxiety can interfere with your rehabilitation.

Psychological therapies can also be useful in helping you cope better with the symptoms of pain. For example, some studies have shown that cognitive behavioural therapy (CBT) can help in the management of long-term pain.

The aim of CBT is to help you understand how your problems, thoughts, feelings and behaviour can affect each other. By discussing and altering how you feel about your condition, CBT can help you cope with your symptoms and make it easier for you to continue with your rehabilitation programme.

Mirror visual feedback is sometimes used to treat people with CRPS 

Your care team

Due to the complex nature of CRPS, a number of different professionals will usually be involved in your care, such as:

a physiotherapist – who can help you improve your range of movement and coordination

an occupational therapist – who can help you improve the skills needed for daily activities

a pain relief specialist – a doctor or other healthcare professional trained in pain relief

a psychologist – a specially trained mental health professional who can help with psychological problems caused by living with long-term pain

a neurologist – a doctor who specialises in the treatment of conditions that affect the nervous system (the nerves, brain and spinal cord)

a social worker – who can provide information and advice about extra help and services 

an employment adviser – who can offer support and advice to you and your employer to help you stay in, or return to, work

These professionals may work with you either individually, or jointly in "Pain Management Programmes" (PMPs). PMPs aim to support you so that you can manage the pain, even if the pain intensity cannot be reduced.