

What is CRPS (Complex Regional Pain Syndrome)?

Learn what is Complex Regional Pain Syndrome, formerly known as RSD (Reflex Sympathetic Dystrophy)

Understanding what CRPS or Complex Regional Pain Syndrome is can help to quickly diagnose the condition, in the hope of a full recovery or a better prognosis.

Informing families, friends, carers and patients with detailed information on what CRPS is, can be vital in order to manage the long term condition.

CRPS (Complex Regional Pain Syndrome) was formally known as RSD (Reflex Sympathetic Dystrophy) is considered to be a multi-system disorder characterised by severe pain; pathological changes of the bones, joints, and skin; excessive sweating; tissue swelling; and hypersensitivity to light touch. It is generally categorised as crps type 1 or crps type 2. (Brence, J. 2014)

Complex Regional Pain Syndrome  (CRPS) or Reflex Sympathetic Dystrophy (RSD) is a painful, debilitating, chronic, sometimes progressive, poorly understood condition that affects approximately 5% of all injuries that occur.

However complex regional pain syndrome doesn’t always progress in everyone to cause severe aggravating pain and other painful symptoms.

Visit our CRPS/RSD page to learn in more detail what CRPS (Complex Regional Pain Syndrome) is, the different types of CRPS and how the CRPS causes a pain cycle to start.

CRPS occurs when both the nervous system and immune system malfunction as they respond to any tissue damage from trauma. The nerves will misfire, sending constant pain signals to the brain. It will usually occur within 1 or more areas of the body typically legs, arms, feet and hands. However it has been known to be in the face, eyes, internal organs and other parts of the body.


The main CRPS signs and symptoms are extreme constant burning or freezing pain that lasts a long time after the incident occurred and is out of proportion to the original injury, swelling (oedema (UK English) / edema (US), extreme colour and temperature changes along with other different signs and symptoms for CRPS/ RSD that will be looked into in depth within the CRPS Signs and Symptoms page.


The level of pain from Complex Regional Pain Syndrome (CRPS) is measured on the McGill pain index or scale and CRPS is considered the most severe chronic pain condition on that scale. Visit our Pain Scale page to see a visual form of that scale.

According to the Yaguda,B. et al. (2014) they said that:

“Complex regional pain syndrome (CRPS) is a chronic, predominantly neuropathic and partly musculoskeletal pain disorder often associated with autonomic disturbances. It is divided into 2 types, reflecting the absence or presence of a nerve injury.”

Is CRPS A Mental Illness?

Research has shown again and again that CRPS is a physical condition. It is not a mental illness even though there are unfortunately still people who believe that.

Research has shown that there is no link between any psychological conditions causing the onset of crps. However due to the constant high levels of pain and the issues caused within the biopsychosocial model of living with this long term condition, CRPS cause go on to cause mental health issues such as PTSD, anxiety, depression, GAD and other psychological conditions.

If you are affected by mental health problems subsequent to your CRPS please ask to be referred for counselling or the mental health team. Learn more about the various psychological treatments available for CRPS via our CRPS blog series.

Please remember that it has been proved through research that Complex Regional Pain Syndrome or CRPS is a physical condition despite what you may hear from a medical professional. Some medical professionals believe that the condition is caused by previous psychological problems, it is NOT. The condition can causes future psychological problems because of the constant amount of pain. Prior psychological or mental health issues don’t predetermine CRPS. CRPS is not in your mind. It is an actual real condition.



According to the NINDS factsheet on CRPS, they state that Complex Regional Pain Syndrome is:




The names for Complex Regional Pain Syndrome / Reflex Sympathetic Dystrophy (CRPS/RSD) as you will see have changed and evolved just like the research of the condition has. As different symptoms have been found the names have changed in some way. This has been by adding or subtracting different phrases or words or actually combining them. Learn more about the different names for CRPS page within the Burning Nights CRPS Support website.



There are considered two (2) main types of Complex Regional Pain Syndrome (CRPS). Complex regional pain syndrome Type 1 and Complex regional pain syndrome Type 2, However there is a third type of CRPS which was added after the 1994 IASP Conference. These are:


Complex Regional Pain Syndrome TYPE 1 or CRPS I

Complex Regional Pain Syndrome type 1 is what used to be known as (RSD) REFLEX SYMPATHETIC DYSTROPHY. There are still many people including doctors and specialists who still refer to CRPS as RSD. It occurs after an illness or an injury that did NOT directly damage a nerve. It is usually a minor or major tissue injury to the extremities. (Mayo Clinic – Causes of CRPS)


Complex Regional Pain Syndrome TYPE 2 or CRPS II

CRPS Type 2 used to be known as CAUSALGIA. This occurs after there has been a known injury to a nerve.

Even though there are the 2 types of CRPS/RSD, the stages and symptoms are the same for both types.


TYPE NOS or CRPS-NOS (Not Otherwise Specified)

According to the CRPS Guidelines from the Royal College of Physicians (2018), they describe crps nos as:

“A third diagnostic sub-type called CRPS-NOS (not otherwise specified) can be considered for patients who have abnormalities in fewer than three Budapest symptom categories, or two (2) sign categories, including those who had more documented signs and symptoms in the past, if current ‘signs and symptoms’ are still felt to be best explained by CRPS”

Type CRPS-NOS was also discussed in the research from Harden R.N, et al (2007)


You may have heard of the terms Hot or Warm CRPS and Cold CRPS. Visit our CRPS/RSD page for more details on these terms.




However unlike other conditions and illnesses there are not millions of pounds in Government funds or charitable donations from the public to help research the condition. This is one of the reasons why Burning Nights CRPS Support was originally founded and became a charity. If you’d like to support the work that Burning Nigths CRPS Support does please consider making a donation or setting up a fundraiser in aid of the charity. Or why not check out the many other ways of making a donation without giving money. accepts donations to help us to continue being a successful UK charity for CRPS. We also now accept both one off and regular donations via Text. To find out more about Text Donations please visit our Text To Donate page




History of Complex Regional Pain Syndrome (CRPS)

Complex Regional Pain Syndrome (CRPS) has been a controversial chronic condition through the centuries since it was first described and diagnosed, making the condition have a very interesting history.

Over the centuries this chronic condition has had in excess of 200 different names and titles in the English language alone. This doesn’t take into account any other languages other than English. Learn more about the different names of CRPS via our website.


What is CRPS? | What is RSD? | History of CRPS | Ambroise Paré
What is CRPS? | What is RSD? | CRPS 1 | History of CRPS | Ambroise Paré | By William Holl (1807-1871) via Wikimedia Commons
The first ever known description of Complex Regional Pain Syndrome was back in the mid 16th Century and the era of French King Charles IX of Valois. Following one of the bloodletting sessions on the King by his surgeon, AMBROISE PARE, after a bout of smallpox, the King described an extreme burning pain in his arm along with other symptoms which included shortening of his arm muscle, inability to stretch and bend the whole arm. Ambroise Pare was also father of modern surgery. The description by Pare is what we would now be related to the current concept of Complex Regional Pain Syndrome (CRPS).
Paré identified also ‘Phantom Limb’ syndrome, which is another chronic painful condition that we now also call Phantom Limb Pain. Phantom Limb pain may occur after an amputation of a limb.
What is CRPS? Understand what RSD is? |  History of CRPS | Sir Percivall Pott | Commons Wikipedia
What is CRPS? | What is RSD? | History of CRPS | Sir Percivall Pott | Commons Wikimedia

After this in the late 1700’s, a British surgeon and one of the founders of orthopaedics by the name of Sir Percivall Pott recognised atrophy (weakness) and burning pain in injured extremities.

However the first written description of CRPS was made by Dr. Alexander Denmark, a British surgeon who worked at the Royal Navy Hospital in Hampshire. He published a case report who had been wounded by a bullet that’s had passed through his upper arm. Dr Denmark found that even though the soldier’s wound had healed, the soldier’s forearm was bent and he had a “burning” pain that was so severe the soldier was always sweating. Unfortunately at the time Dr Denmark’s accurate clinical case report was ignored until a few decades later other clinical cases of gunshot wounds that occurred in the American Civil War were not ignored. Dr Denmark linked the persistent and burning pain to the involvement of the radial nerve in the gunshot injury of the upper arm. (Denmark A. 1813)




What is CRPS? | What is RSD? | CRPS Type I | CRPS Type II | History of CRPS Silas Weir Mitchell
What is CRPS? | What is RSD? | CRPS 1| History of CRPS Silas Weir Mitchell | By Unknown. (Images from the History of Medicine (NLM).) [Public domain], via Wikimedia Commons
After this, the next description was by SILAS WEIR MITCHELL MD during the American Civil War (1861-1865), is the one that most academics refer to as the birth of CRPS. Silas Weir Mitchell MD was an American doctor who during the war treated soldiers with nervous conditions or injuries and those with gunshot wounds. By the end of the Civil War he had become a neurology specialist. His description of persistent burning pain around 1864 felt by those soldiers whose bullets had been removed a long while ago was eventually called CAUSALGIA which is what everyone knows today as Complex Regional Pain Syndrome / Reflex Sympathetic Dystrophy (CRPS/RSD). Mitchell believed that the burning pain was because of an injury to a nerve and in his book from 1872, “Injuries of Nerves and Their Consequences,” he wrote that the pain that the soldiers and veterans felt was “the most terrible of all the tortures which a nerve wound may inflict.” Silas Mitchell found that the location of the pain did differ in every patient but that it had mainly concentrated in the hand or the foot.


What is CRPS? | History of CRPS | Dr Jean-Martin Charcot via Burning Nights CRPS Support | Wikipedia Commons
What is CRPS? |What is RSD | History of CRPS | Dr Jean-Martin Charcot via Burning Nights CRPS Support | Wikimedia Commons


Dr. JEAN-MARTIN CHARCOT was the French doctor who began thinking that the condition caused swelling, temperature and colour changes were shown as signs. However he was the doctor that began to say that it CRPS was a product of our brain’s thinking and suggesting it to us – i.e. psychosomatic, autosuggestion if you like. The neurologist outlined it as hysteria minor and even now there are doctors and specialists that will say that it is a disease or disorder that has been auto-suggested – or even in your head!




What is CRPS? | What is RSD? | History of CRPS | Dr Paul Sudeck via Commons Wikimedia

One of the other main doctors concerned with Complex Regional Pain Syndrome / Reflex Sympathetic Dystrophy was called Dr.PAUL HERMAN MARTIN SUDECK who was a German doctor who lived 1866-1945. Sudeck was the doctor where we get the phrases such as Sudeck’s Dystrophy or Sudeck Atrophy (this was later known as Reflex Sympathetic Dystrophy (RSD)) Sudeck’s Disease or Sudeck’s Syndrome. He first described the condition in around 1900 and discussed the possible cause of over response following an accident that caused an injury, bone break or surgery. Sudeck also said that it was inflammation reply which had various symptoms or signs that included amongst other things pain and differing colours. There was also the discussion with the Sudeck’s Atrophy of osteoporosis. As you know these things are all what we use now as indicator signs and symptoms of modern day CRPS/RSD.

What is CRPS? | What is RSD? | History of CRPS | René Leriche circa 1915 via Commons Wikimedia

Another military surgeon, a Frenchman named Dr. RENE LERICHE was known for also treating soldiers with nerve damage but this was during World War I. He wrote about what we would know as the characters of ‘modern’ Complex Regional Pain Syndrome. His idea of getting rid or ease the pain was to perform a sympathectomy (this is an operation where the sympathetic nerve is cut mainly to ease the pain) on the soldiers, as he believed this was the successful treatment for CRPS/RSD. We would consider this a very last resort now, but then it was very different and little true knowledge as little was known at that time. Leriche talked about sweating of the skin, intense burning pain and the mental side of the condition. He was constantly distressed at the constant burning pain the soldiers were having and he wrote the ‘Surgery of Pain’ (‘La Chirugie de la Douleur’) in 1937.

Around 1936 there was also a German student called REIDER and he was a pupil of Dr. Sudeck. Reider decided that because of the way the condition travels that the phrase ‘Reflex’ and because he saw the bone tissues wasting the used the term ‘limb dystrophy.’




The next major authority for Complex Regional Pain Syndrome/Reflex Sympathetic Dystrophy again another military doctor in and around the time of World War II, he was WILLIAM K. LIVINGSTON MD and who lived 1879-1966. His job saw him at a Naval Hospital in USA and he mainly dealt with soldiers who had problems with chronic pain because of damage to their Peripheral Nervous System (PNS). The PNS consists of nerves and any nerve cell clusters (Ganglia) which are outside of the spinal cord and the brain. Its main job is to communicate between the central nervous system and the limbs. Livingston spoke about the pain spreading to other limbs and is also known as the forbearer of the foundation of chronic pain that we actually still use today. Livingston developed more Leriche’s theory of the ‘Catch-22’ or the theory of the vicious circle.


Osteoporosis was again authenticated by another German Doctor; ROBERT KIENBÖCK. He believed that CRPS/RSD osteoporosis was down to not using the limb thereby causing muscle and bone wastage. A variation of CRPS was also deliberated by the Doctor called Kienböck’s atrophy or Kienböck’s syndrome. This is simply very much like CRPS / RSD and it has acute bone wastage.


Over the history of CRPS/RSD there have been many other doctors and surgeons who have added more signs, symptoms and name for the modern day Complex Regional Pain Syndrome. These eminent people included a doctor by the name of Dr. JAMES EVANS just after World War II in approximately 1946 he devised the term of REFLEX SYMPATHETIC DYSTROPHY(RSD) and he thought that there was contribution of hyperactivity of the sympathetic nervous system. The term of RSD was then used right up to the 1993/1994 conference of the International Association of the Study of Pain (IASP) when we finally have what the term is today – COMPLEX REGIONAL PAIN SYNDROME (CRPS.) There was ‘Shoulder-hand Syndrome’ the brainchild of a doctor named STEINBROCKER in around 1947. A few years later in approximately 1953 and he started the use of steroids by mouth or as they medically known ‘corticsteroids.’ Another doctor was HANNINGTON-KIFF who began to treat CRPS/RSD with the intravenous blocks using Guanethidine in around 1974.




To try and diagnose the chronic pain condition and some of its symptoms, various types of methods were used. Those included were the Three Phase Nuclear Scans’ instigated by a doctor named FRANKLIN KOZIN (still used now in RSD diagnosis) in the USA. Nuclear scans also originated in France by a doctor called SERRE, H. Temperatures of the limbs of suspected CRPS/RSD patients had the thermography assessed by using a reflecting telescope, and then later DR R. LAWSON produced recordings of temperatures from American soldiers suspected of having the condition during the Korean War.


After all of the different terminology, symptoms and ways of diagnosing the condition in around 1995 Dr. JUDITH A. PAICE wrote that even though a name for the condition had been decided in the IASP, still after 130 years of discussion nobody would agree to the best way of treating the condition, how it is caused or even what to name it. So, CRPS or Complex Regional Pain Syndrome is the name for the moment, but who knows this may change again in the future.


Did you know there’s been over 200 different names for CRPS? Why not check out some of those other names for CRPS on our Different Names page?!

SO… After all of the History of CRPS, the chronic and progressive pain condition – we’re still not really any clearer to understanding the reasons of how it happens, why it happens, what we can do to treat the symptoms even if we can’t treat the actual chronic pain disorder. We need to try and reduce or even stop the symptoms from progressing using research. Understanding what CRPS/RSD is, and the 2 main types of CRPS – CRPS Type 1, CRPS Type 2 and the CRPS sub-type – CRPS-NOS, are integral parts of living with this condition and starts you on the road to acceptance.







Written: 01/08/2014

Last Updated: 17/07/2019

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