According to specialists and doctors who deal with CRPS patients, the actual cause or how you can 'get' Complex Regional Pain Syndrome (CRPS) is as of yet unknown. However, research does say that CRPS most likely does not have a single cause, but multiple causes. (Web MD)
Although men and women can develop Complex Regional Pain Syndrome, research has found that it does affect more women than men (3-4.1) (de Mos et al 2007). CRPS in children also affects more girls than boys.
In a research study by Lee, W.H. (2015) it was concluded that there were a number of possible causes of Complex Regional Pain Syndrome including: "…tissue damage, nerve damage, casting, traumas, fractures, burns, frostbites, strokes, and other non-identifiable causes"
It has been noted among health professionals that Complex Regional Pain Syndrome (CRPS) may develop or be triggered after any of the following incidents:
The list above is by no means definitive and there are cases where the CRPS patient doesn't even know how or when an incident occurred for the Complex Regional Pain Syndrome to be triggered.
Although CRPS is caused by trauma in most cases, there are 10% or below of spontaneous cases of CRPS, where there has been no known reason or cause for the start of the condition. This occurs a lot in children or teenagers who may not realise that they have experienced any damage to themselves. However, this isn’t always the case.
CRPS can develop in both upper and lower limbs, but there are approximately 60% of cases of upper limb CRPS and 40% of cases of lower limb CRPS. This doesn’t mean that the condition can’t be triggered in other areas of the body.
In the 2011 research by Goebel, A. it is stated that significant scientific and clinical advances over the preceding 10 years hold promise for an improved understanding of the causes of CRPS. Therefore, research is still ongoing into what causes Complex Regional Pain Syndrome. CRPS is a chronic neuropathic pain condition that may affect different systems within the body including the sympathetic nervous system, which is why no one person diagnosed with CRPS will have the exact same symptoms as someone else.
Janig & Baron (2003) stated that: "On the basis of clinical observation and research in human beings and animals, we hypothesise that CRPS is a systemic disease involving the CNS and peripheral nervous system."
The NINDS website on CRPS (2018) gives a description of how a person can get CRPS or what triggers the condition as "CRPS represents an abnormal response that magnifies the effects of the injury. In this respect it is like an allergy. Some people respond excessively to a trigger that causes no problem for other people."
The syndrome usually will affect one (1) or more regions of the body, for example arms, hands and legs; however, there are cases of people who have CRPS in the whole of their body or in their internal organs or facial area.
The two main types of CRPS are CRPS Type I, a classification formerly referred to as Reflex Sympathetic Dystrophy Syndrome, which happens where there is no certain damage to a nerve, and CRPS Type II (previously called Causalgia) where there is a direct injury to a nerve. When CRPS is developed, the pain that is felt is totally out of proportion to the actual injury, such as following a fracture or broken bone. There are occasions where the syndrome has onset but there has been no actual cause or reason for it. There is also a third type known as CRPS-NOS or CRPS Not Otherwise Specified (RCP Guidelines for CRPS 2018).
According to the Mayo Clinic website (2014), a possible cause for CRPS: "...may be due to a dysfunctional interaction between your central and peripheral nervous systems and inappropriate inflammatory responses."
In a study from 2014 by Moseley, G.L. et al. it was mooted that if someone who had fractured their wrist had a pain intensity of 5/10 or more on average for two days then this should be a red flag for Complex Regional Pain Syndrome (CRPS).
Researchers have found in their studies into the causes of CRPS that they believe it begins because of an abnormal response to an injury that has resulted in four main systems in the body to malfunction.
These 4 main systems include (NHS Choices):
Goebel, A. (2011) explains that: "The condition's distinct combination of abnormalities includes limb-confined inflammation and tissue hypoxia, sympathetic dysregulation, small fibre damage, serum autoantibodies, central sensitization and cortical reorganization."
Another theory posited in a Web MD article (2015) suggests that: "… pain receptors in the affected part of the body become responsive to catecholamines, a group of nervous system messengers."
More research has to be done into Complex Regional Pain Syndrome, including finding out more about its causes and triggers. One way to contribute to improving the amount of research into CRPS - such as how the condition is developed, its signs and symtoms, and how it can be treated - you can contact your regional MP (or Senator for those outside the UK). You could also contact the various MPs concerned with health and disability and tell them about yourself and talk about the lack of research available for CRPS.
Burning Nights CRPS Support has worked with their local MP to get recognition for CRPS and has started an Early Day Motion (EDM). Please visit our 'Campaign To Raise Awareness of CRPS In Westminster' article, which includes a template letter you can amend for your local MP.
Living with Complex Regional Pain Syndrome can be complex and after being diagnosed with CRPS, you often don't know why you have got the condition or what caused the signs and symptoms to start. This is why we have information on all areas of life with CRPS including how you can 'get' CRPS, i.e. what causes CRPS or what triggers CRPS. Understanding how you can get CRPS or what are the main known causes of CRPS is an integral part of learning about Complex Regional Pain Syndrome (CRPS).