Complex Regional Pain Syndrome (CRPS)

This article is about Complex Regional Pain Syndrome, which is commonly abbreviated to CRPS. This is a poorly understood condition but I’m going to look into what we do know about it based on the latest research. We will look at what the symptoms are, what we think causes it and the treatment options that show the most promise. The information can also be seen in video format below.

What is CRPS ?

Well it’s 'Complex', because we don’t understand fully what is happens to the body in CRPS, and why it occurs in some people and not others. Its 'Regional', in thats it tends occur in an isolated area, usually a hand or a foot. Its 'Painful' - which is the main symptom, and its a 'Syndrome', meaning that it consists of set of symptoms that tend to occur together but we don’t fully understand the link between them, the exact cause of the condition, or have a clear treatment path.

So what do we Know ? 

Well it usually starts after an injury to an arm or leg. But where the normal response is that the pain improves over time as the injury heals, in CRPS there is an abnormal pain response to the injury. The pain becomes out of proportion to the injury and persists even after it's healed. 

Pain after injury is useful, because it helps you to protect the injured area while it’s healing. But in CRPS the pain is unhelpful. It serves no good purpose. The original injury has often healed a long time ago but this abnormal pain response continues without rhyme or reason. 

The Nervous System and the Brain are all affected in CRPS. Essentially the brain responds abnormally by producing a painful sensation, to things that would not normally be painful. 

What are the Symptoms ? 

The main symptom of CRPS is Pain, which can be severe. The type of pain experienced can be variable and include burning, stabbing or stinging sensations and also painful tingling and numbness.

The skin over the affected limb can become extremely sensitive to touch. Sometimes just a small knock or a simple brush against the skin can cause an extreme, heightened pain response. We call this ‘Hyperalgesia’ which means an exaggerated pain response, or ‘Allodynia’ which means a painful response to a stimulus that is usually not painful, such as light touch or gentle pressure.

Patients can also describe strange sensations such as feeling like the limb is bigger or smaller than the other side, or that it just doesn’t belong to them. Other symptoms include swelling of the limb, changes in skin colour and temperature and the hair and nail growth can be affected. 


As the pain persists, joint stiffness and muscle weakness can occur to the degree where the patient might struggle to move the affected limb, or put weight through it if the leg/foot is affected. 

The persistent pain and resulting sleep disturbance can often lead to mood changes, stress, anxiety and social isolation, sometimes leading to clinical depression and psychological trauma.

What causes CRPS ?

CRPS usually occurs after an injury to a limb such a fracture, a burn or soft tissue trauma such a sprain, a deep cut or crush injury. It can also occur after surgery. Symptoms usually start within a month of injury, at the point when you would expect the pain to be improving, but instead the pain gets worse and often spreads well outside the injured area, sometimes involving the whole arm or leg. 

Why some people develop CRPS is not well understood but it does tend to be more common within families, suggesting a possible genetic predisposition. It also tends to be more common if the patient has undergone additional recent stress or anxiety.

How is CRPS diagnosed ?

There is no simple test for CRPS. It’s usually a diagnosis of exclusion, meaning that it’s diagnosed after all other explanations have been ruled out. So if you have worsening pain 6 weeks after eg. a wrist injury, when you would have expected it to be getting better, then your doctor might be concerned and arrange an X-Ray and if thats normal, an MRI scan. Blood tests can rule out other causes and nerve conduction tests can check for nerve injury.

If all these tests come back showing nothing abnormal then a diagnosis of CRPS might then be considered. The main physical features are the colour changes or swelling of the limb and the exaggerated pain response to difference stimulations including touch, pressure and temperature changes.

Once CRPS is diagnosed then patients will usually be referred to a specialist pain clinic, usually consisting of a team of physiotherapists (or physical therapists in the US), nurses and doctors specialising in pain medicine, occupational therapists and clinical psychologists. 

How is CRPS treated ?

Unfortunately there is no known cure for CRPS. Current research shows that a combined approach using physical treatments, medical treatments and psychological support can reduce the symptoms of CRPS in around 85% of patients over about 2 years. So it’s a long process involving different treatment techniques and different clinicians. 

What works for one person may be different to others and so the job of the pain clinic team is to help find out which treatments work best for you and then come up with a plan to suit your needs.

Your treatment will usually consist of 4 main pillars; Education and Self Management, Physical Rehabilitation, Pain Relief Medicines and Psychological Support. So let’s look at each of these.

1) Education 

Education is really important in managing CRPS. Its a long recovery process and if the patient is going to stick with it and keep going, especially on the bad bays when frustration and doubt set in, then its vital that they have a clear understanding of what they are doing and why. And they have realistic expectations about their goals and recovery times. 

Hand in hand with education is Self Management. Someone with CRPS might spend just an hour a week, or less, with the pain team and so it’s vital that they are doing everything they can to help themselves for the rest of their time. Self management is likely to include regular exercises tailored to your needs, relaxation techniques, pain management strategies, pacing your activities to avoid causing a flare up, and accessing local support groups.

2) Physical Rehabilitation 

Physical activity forms the backbone of CRPS treatment. It’s likely to involve specific exercises, stretches and functional activities which you can build on and progress. Exactly what you do, how often you do it and with how much intensity will be individual to you and will hopefully change over time as you make progress. The pain team therapists will guide you along this journey.

Another key part of the physical treatment are the Desensitisation Techniques which are used to help reduce the extreme pain sensitivity that people experience with CRPS. This might involve something called Graded Exposure, where the limb, hand or foot is exposed to mild & tolerable sensations which become progressively more challenging in baby steps over time. 

Using Graded Exposure to break a Task down into Manageable Chunks

This is an attempt to help the brain and nervous system re-learn the right way to process touch, temperature, vibration etc. This might involve touching the limb with different textures and materials in a way that the patient can tolerate with minimal pain and doing this with enough repetition so that the brain begins to learn that this is a non-threatening action that shouldn't require a pain response. 

Another commonly used desensitisation technique is something called Graded Motor Imagery. This is a technique backed up by the latest science and clinical research and works by helping the brain relearn movement patterns in the painful limb by accessing the normal movement patterns of the non painful limb. There are different techniques for doing this but one of the commonly used ones is Mirror Box Therapy as it can be used by the patient at home with minimal equipment. 

Mirror Box - Link to Product

Ive written a separate article all about mirror box therapy which you can see here

And the very latest research in graded motor imagery is looking at how Virtual Reality can be used in a similar but much more immersive way to help train the brain to access those non-painful movement patterns and hopefully speed up the recovery process.

VR Headset

3) Medical Management

This will largely consist of drugs used to help dull the pain. There many different drugs used in CRPS and this is going to be very individual to your specific needs. I’m not going to discuss all the available drugs but the ones used in CRPS by pain clinics tend to fall in to 4 categories, and it may be that you will take a combination of drugs from the different categories to help you. Please note that the drugs names I’m using here are from the UK and so there might be differences in the brand names used in your country. 

First are the Non Steroidal Anti-Inflammatory Drugs, often shortened to NSAID’s. This included aspirin and ibuprofen, which can be bought over the counter in most countries, and also ones which are usually prescribed such as Naproxen, Diclofenac, Celecoxib and Indomethicin. 

The next category of drugs commonly used are the Anticonvulsants. These are essentially anti-epileptic drugs which have also been found to help reduce neuropathic pain such as in CRPS. The commonly used drugs in this category are the Gabepentinoids; Gabapentin and Pregabelin.

Next we have the Tricyclic Antidepressants which have also been found to help with neuropathic pain. The common ones used are Amitriptyline and Nortriptyline. 

Finally, we have the Opioids, which contain Codeine or Morphine. There are many different drugs in this category with many different brand names. and they can be delivered by tablets, liquid, suppositories or transdermal patches. They tend to have more side effects that some of the other drugs, particularly constipation, nausea, dry mouth and they can affect concentration. They also have addictive properties and so tend to be carefully managed by the medical staff within the pain team or the family doctor. 

Spinal Cord Stimulation

The last medical treatment I’m going to mention is not a drug at all, it’s a type of electrical therapy called Spinal Cord Stimulation. It’s usually considered only if significant pain is still a problem after at least 6 months of trying the other treatments. 

Spinal Cord Stimulation

It involves surgically placing small electrodes next to the spinal cord in either the neck, for arm symptoms, or the lower back, for leg symptoms. The leads are then connected to small device containing a battery which is implanted just beneath skin, usually in your belly. It can be turned on or off by the patient and clinical trials have found it to be an effective pain relief treatment for many people with CRPS.

4) Psychological Support

Living with chronic pain, which disturbs sleep and limits your ability to function normally can be an enormous burden on your mental health. Anxiety and depression are commonly seen in CRPS and so Clinical Psychologists are a key component of the pain management team. 

A commonly used technique is Cognitive Behavioural Therapy (CBT). This can be delivered individually or in small groups and it aims to encourage self reflection, openness and honesty regarding your thoughts, feelings and behaviour and how they can affect your symptoms and the way you interact with people around you. We know that anxiety, depression and poor mental health can significantly worsen the symptoms of chronic pain and so by addressing these issues, the symptoms of pain in CRPS can also be improved.


CRPS can be a debilitating condition that can take many years to resolve. If you think you might have CRPS then do get medical help and ask about a referral to a specialist pain clinic. If you’ve been diagnosed with CRPS or you know someone with it then I hope you’ve found the article helpful. Do try to stay positive and also try and seek out local support groups as it can be long recovery which can be made much easier if shared with others in the same situation. 


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