Complex Regional Pain Syndrome (CRPS) Info Evidence
Reviewed by Dr Kieran Hirpara, Specialist Orthopaedic Surgeon Last reviewed
What you're feeling
You may notice pain that feels deeper or sharper than a normal ache. This is not just surface soreness. It is a sign that your nerves are sending mixed signals. The pain often stays in one limb, such as your hand or foot. It can feel like burning, throbbing, or a constant tingling sensation. You might find that even a light touch from clothing feels uncomfortable or painful.
Your daily tasks may become difficult. Simple actions like holding a coffee cup or buttoning a shirt can feel hard to manage. You might notice swelling or changes in skin colour in the affected area. The pain often flares up at night, making it hard to settle into sleep. It can also worsen after you have been active during the day. When you first wake up, your limb may feel stiff or unusually sensitive.
We know that early recognition of these symptoms is important. Prompt treatment helps to protect your function and reduce the risk of long-term issues. However, we also want to be clear that some patients may still experience lasting effects despite treatment. We use tools like the Hamilton Inventory to track your symptoms and how they affect your life. This helps us understand the full picture of your pain, including any stress or mood changes that come with it.
If you are experiencing unusual chronic pain, we will look at all possible causes. CRPS is a diagnosis of exclusion, meaning we rule out other conditions first. We may use quantitative sensory testing to understand how your pain mechanisms differ from typical responses. This helps us tailor a plan that addresses the specific way your body is reacting.
What's actually happening
Your body’s pain system has become overly sensitive. In Complex Regional Pain Syndrome, the nerves that send signals from your skin and joints to your brain get stuck in a high-alert state. Think of it like a smoke alarm that goes off when you are just boiling water, instead of only when there is a real fire. The alarm is loud and persistent, even though there is no immediate danger.
This sensitivity causes your pain levels to feel much stronger than they should for the injury you have. Tests show that your ability to sense touch and temperature changes is altered compared to people without this condition. Your brain is interpreting normal sensations as painful. This is why even light clothing or a gentle breeze can feel uncomfortable or sharp.
The condition often starts after an injury, surgery, or nerve irritation. It is not caused by new damage to the bone or tissue, but by how the nervous system processes the existing signals. While early treatment helps prevent long-term stiffness, some people may still experience lasting changes in how their limb feels or moves.
We know this can be confusing and frustrating. Your doctor explains that the goal is to calm this overactive alarm system. By addressing the pain early, we aim to protect your function and help your nerves return to a more normal rhythm.
What we can do about it
We start with active self-management and physiotherapy. An active approach helps lower the chance of developing CRPS-1. Your physiotherapist will guide you through gentle movements. The goal is to restore function and reduce stiffness. You should give this phase enough time to work. Consistency matters more than intensity at first. We use tools like the Hamilton Inventory to track your progress. This helps us see how symptoms affect your daily life. Early recognition and prompt treatment are important. They help minimize permanent loss of function. However, please know that some patients may still experience permanent impairment.
Medical management focuses on pain control and reducing inflammation. Your doctor may prescribe pain medication to help you move comfortably. Anti-inflammatory drugs can also play a role in managing symptoms. In some cases, prednisolone is considered as a treatment option. This is particularly useful in settings where specialized interventions are not available. For chronic or refractory CRPS, ketamine may be strongly considered. It targets altered pain mechanisms in the body. Quantitative sensory testing can help identify these changes. It shows how your pain response differs from typical controls. We weigh the benefits of these medications against potential side effects. The aim is to find a balance that allows you to participate in therapy.
If symptoms remain severe despite these measures, we may refer you for specialist assessment. A diagnosis of CRPS is clinical, based on your history and physical examination. We look for specific signs to confirm the condition. For some specific conditions, such as CRPS following carpal tunnel release, a large percentage of patients can have full resolution of symptoms with the procedure. Similarly, outcomes after collagenase injection for Dupuytren’s contracture can be encouraging. However, risk factors like female sex, manual labor, or elderly age may influence outcomes after certain surgeries. We discuss these individual risks with you. If a procedure is occasionally considered, it is part of a broader plan to restore your function and quality of life.
What to expect
Your doctor will diagnose Complex Regional Pain Syndrome based on your history and physical examination. Early recognition and prompt treatment are important to minimize permanent loss of function. However, even with early care, you may still experience permanent impairment and disability.
A more active treatment approach appears to lower the incidence of this condition. For many patients, symptoms can resolve fully. A large percentage of patients diagnosed with CRPS type 1 can have full resolution of their symptoms with carpal tunnel release. Similarly, a positive outcome is encouraging for patients with Dupuytren’s contracture treated with collagenase injection.
If left alone or if treatment is delayed, the condition may persist. The incidence of CRPS following isolated cubital tunnel surgery is approximately 0.33% at 1 year. For other procedures, such as arthroscopic rotator cuff repair, CRPS-related hand lesions developed in 19.4% of patients. Certain factors increase your risk, including being female, older age, manual labor, or releasing more than one digit during hand surgery.
Recovery varies. High-intensity laser therapy offers conclusive evidence of pain reduction, even after the third treatment session. Prednisolone is a potential treatment option, particularly where specialized interventions are unavailable. For chronic or refractory cases, strong consideration is given for the use of ketamine.
You might wonder how long symptoms last. The reported incidence is influenced by diagnostic criteria and study location. While some patients recover quickly, others face a longer road. Your doctor will monitor your progress using tools like the Hamilton Inventory to assess symptoms and functional limitations.
We aim to manage your pain and restore function. We use quantitative sensory testing to understand altered pain mechanisms compared to controls. While non-pharmacological treatments for upper limb CRPS often have poor methodological quality, we tailor your plan to your specific needs.
Your outlook depends on how quickly you start treatment and the specific cause of your CRPS. With active management, many patients see significant improvement. Without it, the risk of permanent issues remains. We will work with you to navigate this multifactorial condition and support your recovery journey.
When to see someone
See your GP if you have persistent pain that does not improve with rest. Ask for a specialist review if you notice weakness, instability, or locking in the joint. Seek care if symptoms interfere with your sleep or work. Sudden worsening of pain is also a reason to act. CRPS is a clinical diagnosis based on your history and physical exam. Early recognition is important to minimize permanent loss of function. Prompt treatment helps manage this multifactorial condition. While some patients recover fully, others may experience lasting impairment. Do not wait for symptoms to resolve on their own. Early intervention offers the best chance to protect your daily activities and long-term mobility.
Evidence & references
Overview
- CRPS is a multifactorial condition that requires further study to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options [3].
- The diagnosis of CRPS is a clinical diagnosis based on history and physical examination [9].
- Early recognition and prompt treatment of CRPS are important to minimize permanent loss of function [9].
- Patients with CRPS may still experience permanent impairment and disability despite early recognition and prompt treatment [9].
- The reported incidence of CRPS is influenced by the choice of diagnostic criteria, the study location, and how the fracture is managed [15].
- A more active treatment approach seems to lower the incidence of CRPS-1 [2].
- The incidence of CRPS following isolated cubital tunnel surgery is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33% [10].
- Quantitative sensory testing outcomes indicate altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5].
- The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4].
- Strong consideration should be given for the use of ketamine in patients presenting with chronic or refractory CRPS [1].
- Prednisolone has potential as a treatment option for CRPS, particularly in resource-limited settings where more specialized interventions may be unavailable [6].
- High-intensity laser therapy (HILT) offers conclusive evidence of pain reduction in CRPS-I, even after the third treatment session [7].
- The methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor [8].
Background & Causes
- CRPS is a multifactorial condition requiring further study to understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options [3].
- Altered pain mechanisms exist in CRPS compared to controls, with a pooled standardized mean difference of -0.41 in quantitative sensory testing outcomes [5].
- The diagnosis of CRPS is clinical, based on history and physical examination [9].
- Early recognition and prompt treatment are important to minimize permanent loss of function, although patients may still experience permanent impairment and disability [9].
- CRPS following isolated cubital tunnel surgery is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33% [10].
- Female sex is a significant predictor of developing CRPS following treatment of Dupuytren contracture [11].
- Release of more than one digit is a significant predictor of developing CRPS following treatment of Dupuytren contracture [11].
- A large percentage of patients diagnosed with and treated for CRPS type 1 can have full resolution of their symptoms with carpal tunnel release [12].
- Elderly patients have a higher risk of developing CRPS after distal radius fracture surgery [13].
- Females have a higher risk of developing CRPS after distal radius fracture surgery [13].
- Manual laborers have a higher risk of developing CRPS after distal radius fracture surgery [13].
- CRPS-related hand lesions developed in 19.4% of patients following arthroscopic rotator cuff repair [14].
- Preexisting neuropathic disorders are the strongest predictors of CRPS after distal radius fracture [17].
- Traumatic nerve injuries are the strongest predictors of CRPS after distal radius fracture [17].
- Compressive neuropathies are the strongest predictors of CRPS after distal radius fracture [17].
- Cervical radiculopathy is the strongest predictor of CRPS after distal radius fracture [17].
- Patients with scaphoid waist fracture may be at higher risk of CRPS type I [19].
- Women with diabetes mellitus who report severe pain before treatment are at higher risk of CRPS type I following scaphoid waist fracture [19].
Symptoms & Presentation
- CRPS is a multifactorial condition [3].
- Quantitative sensory testing indicates altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5].
- Pain is a highly debilitating symptom in CRPS-I [7].
- The diagnosis of CRPS is based on history and physical examination [9].
- CRPS should be considered a diagnosis of exclusion [18].
- Glomus tumors should be included in the differential diagnosis for patients with unusual chronic pain or neuropathy [18].
- The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4].
- CRPS-related hand lesions developed in 19.4% of patients following arthroscopic rotator cuff repair [14].
Management
- Strong consideration should be given for the use of ketamine in patients presenting with chronic or refractory CRPS [1].
- A more active treatment approach seems to lower the incidence of CRPS-1 [2].
- The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4].
- Quantitative sensory testing outcomes indicate altered pain mechanisms in complex regional pain syndrome compared to controls, with a pooled standardized mean difference of -0.41 [5].
- Prednisolone has potential as a treatment option for CRPS, particularly in resource-limited settings where more specialized interventions may be unavailable [6].
- High-intensity laser therapy (HILT) offers conclusive evidence of pain reduction in CRPS-I, even after the third treatment session [7].
- The methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor [8].
- The diagnosis of CRPS is a clinical diagnosis based on history and physical examination [9].
- Early recognition and prompt treatment of CRPS are important to minimize permanent loss of function, though patients may still experience permanent impairment and disability [9].
- The incidence of CRPS following isolated cubital tunnel surgery (CuTS) is approximately 0.33% at 1 year [10].
- Female sex is a significant predictor of developing CRPS following treatment of Dupuytren contracture [11].
- Release of more than one digit is a significant predictor of developing CRPS following treatment of Dupuytren contracture [11].
- A large percentage of patients diagnosed with and treated for CRPS type 1 can have full resolution of their symptoms with carpal tunnel release [12].
- Elderly patients have higher risks of developing CRPS after distal radius fracture surgery [13].
- Female patients have higher risks of developing CRPS after distal radius fracture surgery [13].
- Manual laborers have higher risks of developing CRPS after distal radius fracture surgery [13].
- A patient with bilateral Dupuytren’s contractures who developed CRPS-1 after fasciectomy had a positive outcome with no relapse on subsequent collagenase clostridium histolyticum (CCH) injection and manipulation of the other hand [16].
Key Considerations
- In patients with chronic or refractory CRPS, strong consideration should be given for the use of ketamine [1].
- A more active treatment approach appears to lower the incidence of CRPS-1 [2].
- CRPS is a multifactorial condition requiring further study to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options [3].
- The Hamilton Inventory can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts [4].
- Quantitative sensory testing outcomes indicate altered pain mechanisms in CRPS compared to controls, with a pooled standardized mean difference of -0.41 [5].
- Prednisolone is a potential treatment option for CRPS, particularly in resource-limited settings where specialized interventions may be unavailable [6].
- High-intensity laser therapy (HILT) provides conclusive evidence of pain reduction in CRPS-I, even after the third treatment session [7].
- The methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor [8].
- CRPS diagnosis is clinical, based on history and physical examination, with early recognition and prompt treatment important to minimize permanent loss of function [9].
- Patients with CRPS may still experience permanent impairment and disability despite early intervention [9].
- The incidence of CRPS following isolated cubital tunnel surgery (CuTS) is approximately 0.33% at 1 year [10].
- Female sex and the release of more than one digit are significant predictors of developing CRPS following Dupuytren contracture treatment [11].
- A large percentage of patients diagnosed with and treated for CRPS type 1 can achieve full resolution of symptoms with carpal tunnel release [12].
- CRPS-related hand lesions developed in 19.4% of patients following arthroscopic rotator cuff repair (ARCR) [14].
- The reported incidence of CRPS is influenced by the choice of diagnostic criteria, study location, and fracture management [15].
- A patient with bilateral Dupuytren’s contractures developed CRPS-1 after fasciectomy but had a positive outcome with collagenase clostridium histolyticum (CCH) injection and manipulation of the other hand [16].
Key Evidence
- [L1] In patients presenting with chronic or refractory CRPS, strong consideration should be given for the use of ketamine. [1] (10.1177/15589447221131847)
- [L3] A more active treatment approach seems to lower the incidence of CRPS-1. [2] (10.1177/1558944719895782)
- [L4] CRPS is a multifactorial condition that still requires further studying to better understand its pathogenesis, epidemiology, genetic involvement, psychological implications, and treatment options. [3] (10.1007/s40122-021-00279-4)
- [L4] It can be relied upon to assess CRPS symptoms, functional limitations, and psychosocial impacts. [4] (10.1016/j.jht.2025.02.004)
- [L1] The systematic review and meta-analysis of quantitative sensory testing outcomes indicates altered pain mechanisms in complex regional pain syndrome compared to controls, with a pooled standardized mean difference of -0.41. [5] (10.1186/s13018-022-03461-2)
- [L4] The report emphasizes the importance of recognizing CRPS and highlights the potential of prednisolone as a treatment option, particularly in resource-limited settings where more specialized interventions may be unavailable. [6] (10.1186/s12891-024-07333-0)
- [L1] The study results offer conclusive evidence of pain reduction, a highly debilitating symptom in CRPS-I, even after the third HILT treatment session. [7] (10.1016/j.jht.2025.02.009)
- [L1] Methodological quality of non-pharmacological treatment approaches for upper limb CRPS is overall poor. [8] (10.1177/17589983221138610)
- [L2] CRPS following isolated CuTS is exceedingly rare, with an overall 1-year incidence rate of approximately 0.33%. [10] (10.1016/j.jhsg.2026.101028)
- [L3] Female sex and release of more than one digit are significant predictors of developing CRPS. [11] (10.1177/1558944720963915)
- [L3] This study demonstrates that a large percentage of patients diagnosed with and treated for CRPS type 1 can have full resolution of their symptoms with carpal tunnel release. [12] (10.1016/j.jhsa.2024.09.024)
- [L3] The occurrence of CRPS is the result of many factors, with elderly patients, females, and manual laborers having higher risks. [13] (10.1186/s12891-024-07948-3)
- [L3] CRPS-related hand lesions developed in 19.4% of patients following ARCR. [14] (10.5397/cise.2021.00080)
- [L1] The reported incidence of CRPS is influenced by choice of diagnostic criteria, along with the study location and/or how the fracture is managed. [15] (10.1177/1758998320910179)
- [L4] The positive outcome for this woman with Dupuytren's and CRPS-I after CCH injection is encouraging. [16] (10.1016/j.jht.2024.09.002)
- [L3] Preexisting neuropathic disorders, particularly traumatic nerve injuries, compressive neuropathies, and cervical radiculopathy, are the strongest predictors of CRPS after distal radius fracture. [17] (10.1016/j.jhsa.2026.01.004)
- [Case_report] Glomus tumors should be included in the differential diagnosis for patients with unusual chronic pain or neuropathy, and the diagnosis of CRPS should only be a diagnosis of exclusion. [18] (10.1177/1558944719895618)
- [L2] Patients suffering from scaphoid waist fracture may be at a higher risk of CRPS I, especially in women with diabetes mellitus who report severe pain before treatment. [19] (10.1186/s12891-021-04977-0)
References
[1] Pharmacologic Treatments in Upper Extremity Complex Regional Pain Syndrome: A Review and Analysis of Quality of Evidence. HAND. 2022. DOI: 10.1177/15589447221131847 [2] Treatment of Distal Radius Fracture: Does Early Activity Postinjury Lead to a Lower Incidence of Complex Regional Pain Syndrome?. HAND. 2020. DOI: 10.1177/1558944719895782 [3] Complex Regional Pain Syndrome: A Comprehensive Review. Pain and Therapy. 2021. DOI: 10.1007/s40122-021-00279-4 [4] Psychometric evaluation of the Hamilton Inventory to evaluate signs and symptoms in patients with Complex Regional Pain Syndrome (CRPS). Journal of Hand Therapy. 2025. DOI: 10.1016/j.jht.2025.02.004 [5] Pain mechanisms in complex regional pain syndrome: a systematic review and meta-analysis of quantitative sensory testing outcomes. Journal of Orthopaedic Surgery and Research. 2023. DOI: 10.1186/s13018-022-03461-2 [6] Complex regional pain syndrome: diagnostic challenges and favorable response to prednisolone. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07333-0 [7] Effect of high-intensity laser therapy and mirror therapy on complex regional pain syndrome type I in the hand area: A randomized controlled trial. Journal of Hand Therapy. 2025. DOI: 10.1016/j.jht.2025.02.009 [8] Person-centred management of upper limb complex regional pain syndrome: an integrative review of non-pharmacological treatment. Hand Therapy. 2023. DOI: 10.1177/17589983221138610 [9] Complex Regional Pain Syndrome. 2021. [10] Incidence and Patient-Level Risk Factors for Complex Regional Pain Syndrome Following Cubital Tunnel Surgery. Journal of Hand Surgery Global Online. 2026. DOI: 10.1016/j.jhsg.2026.101028 [11] Separating Fact From Fiction: A Nationwide Longitudinal Examination of Complex Regional Pain Syndrome Following Treatment of Dupuytren Contracture. HAND. 2020. DOI: 10.1177/1558944720963915 [12] Outcomes of Median Nerve Release in Complex Regional Pain Syndrome Type 1 of the Hand: A Prospective Case Series. The Journal of Hand Surgery. 2025. DOI: 10.1016/j.jhsa.2024.09.024 [13] Dynamic risk factors for complex regional pain syndrome after distal radius fracture surgery: multivariate analysis and prediction. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07948-3 [14] Clinical outcome in patients with hand lesions associated with complex regional pain syndrome after arthroscopic rotator cuff repair. Clinics in Shoulder and Elbow. 2021. DOI: 10.5397/cise.2021.00080 [15] What is the incidence of complex regional pain syndrome (CRPS) Type I within four months of a wrist fracture in the adult population? A systematic review. Hand Therapy. 2020. DOI: 10.1177/1758998320910179 [16] The case of a woman with bilateral Dupuytren’s contractures who developed CRPS-1 after fasciectomy with no relapse on subsequent collagenase clostridium histolyticum injection and manipulation of the other hand: Considerations for implementing a Budapest criteria checklist and assessing vasomotor instability by measuring differences in skin temperature. Journal of Hand Therapy. 2025. DOI: 10.1016/j.jht.2024.09.002 [17] A Nationwide Propensity Score-Matched Analysis Identifying Preinjury Predictors of Complex Regional Pain Syndrome Following Distal Radius Fracture. The Journal of Hand Surgery. 2026. DOI: 10.1016/j.jhsa.2026.01.004 [18] An Unusual Case of Periosteal Glomus Tumor at the Metacarpal Base Presenting as Type II CRPS: Case Report. HAND. 2020. DOI: 10.1177/1558944719895618 [19] Determinants of complex regional pain syndrome type I in patients with scaphoid waist fracture- a multicenter prospective observational study. BMC Musculoskeletal Disorders. 2022. DOI: 10.1186/s12891-021-04977-0
