Complex regional pain syndrome (CRPS)

What is complex regional pain syndrome?

Complex regional pain syndrome (CRPS) is a chronic pain condition that usually develops in a limb after an injury, surgery, or sometimes a relatively minor trauma. It is defined by continuous regional pain that is disproportionate to the inciting event, combined with a specific cluster of sensory, autonomic, motor and tissue (trophic) changes in the affected limb^1,2,3. CRPS is recognised by the International Association for the Study of Pain and is classified in the World Health Organization's ICD-11 as a chronic primary pain condition^4,2.

There are two recognised types. CRPS type I (formerly reflex sympathetic dystrophy) occurs without an identifiable nerve injury and accounts for most cases. CRPS type II (formerly causalgia) involves overt damage to a specific peripheral nerve^5,3. Both share the same diagnostic features and are managed with similar approaches.

What distinguishes CRPS from other chronic pain conditions is the combination of features in the affected limb:

• Sensory changes. Severe burning or aching pain, often with hypersensitivity to light touch or temperature.
• Autonomic changes. Differences in skin colour, temperature, sweating or swelling compared with the unaffected side.
• Motor changes. Weakness, tremor, reduced range of motion, and sometimes dystonia.
• Trophic changes. Changes in hair, nail or skin texture over time.

CRPS is rare. Estimates of incidence vary between studies but are typically in the order of 5–26 cases per 100,000 person-years, with women affected more often than men³. Many people with CRPS sit within the broader Australian chronic pain population (roughly one in five adults), but the specific recognition, severity and care pathway are different⁶.

CRPS is real, and recognition matters

If you have been told your CRPS is psychological, “made up”, or that you are exaggerating, that is not consistent with current evidence. CRPS is a recognised disorder with formal diagnostic criteria (the Budapest Criteria, validated and adopted internationally), identifiable physical signs on examination, and a substantial and growing body of research into its mechanisms^1,2,3. Diagnosis requires both the symptoms a person reports and the signs a clinician can observe at examination: it is not a diagnosis made on history alone.

The science on what drives CRPS has advanced significantly over the past decade. Current understanding involves peripheral inflammation, changes in the function of small nerve fibres, central nervous system reorganisation, and in some cases possible autoimmune contributions^3,7. Australia is a global research leader in this area, with much of the work on graded motor imagery and rehabilitation led by researchers at the University of South Australia and NeuRA^8,3.

Recognition matters because early diagnosis and treatment substantially affects outcomes^5,3. Most clinical guidelines emphasise that the best chance of meaningful recovery comes with multidisciplinary treatment started in the first months. If you are past that window, treatment can still help, but it tends to take longer and progress can be slower. The honest framing across guidelines is that some people with CRPS recover well, some experience meaningful but partial improvement, and a smaller group continue to live with significant symptoms despite best treatment^3,5.

What current evidence says about CRPS care

International and Australian guidance is consistent: CRPS care should be multidisciplinary, functional, and started as early as possible^5,3,9,10. The structure of effective treatment combines several elements.

Functional rehabilitation is the foundation. The aim is to gradually restore movement, use and sensory input to the affected limb without provoking the kind of flare that sets recovery back. This is where physiotherapy and occupational therapy play a central role, and where CRPS rehabilitation differs from rehabilitation for most other pain conditions: pushing too hard can worsen the condition, but avoiding the limb entirely allows it to worsen too^5,3.

Graded motor imagery and mirror therapy have the strongest non-pharmacological evidence base specific to CRPS. Graded motor imagery (GMI) is a three-stage rehabilitation program (limb laterality recognition, motor imagery, then mirror therapy) developed and tested in multiple Australian-led trials⁸. Mirror therapy uses the reflection of the unaffected limb to give the brain the visual experience of normal movement on the affected side, which over time reduces pain and improves function in many patients^8,3. These approaches are counterintuitive but have meta-analysis-level evidence and are recommended in current practical guidelines⁵.

Pain neuroscience education (understanding what pain is, why it sometimes persists after an injury heals, and how the nervous system can become sensitised) has consistent evidence as part of multidisciplinary CRPS care and underpins how rehabilitation is approached¹¹. Psychological support, particularly cognitive behavioural therapy, addresses the distress, fear of movement and depression that often accompany CRPS, not because CRPS is psychological, but because living with it has a substantial psychological impact^12,13.

Medication in CRPS is largely extrapolated from the broader neuropathic and nociplastic pain literature: the evidence base specific to CRPS is more limited than for other pain conditions^5,3,14. Common options include the medications used in neuropathic pain (tricyclic antidepressants, gabapentinoids and SNRIs), bisphosphonates in selected acute cases, and short courses of corticosteroids early in the condition. Interventional options such as sympathetic nerve blocks or spinal cord stimulation are considered in refractory cases under specialist pain medicine care, though evidence varies and these are not first-line^3,5.

How Pain Coach is built for CRPS

Pain Coach is a chronic pain tracking app designed to be used with your pain specialist, neurologist, GP or physiotherapist. For CRPS, the daily check-in captures pain alongside the five lifestyle factors that influence chronic pain (sleep, exercise, nutrition, stress and social connection) in under two minutes a day.

CRPS rehabilitation is unusual in that the right dose of activity matters enormously: too much can trigger a flare that sets recovery back weeks, while too little allows the condition to entrench⁵. Tracking activity and function alongside pain shows you and your physiotherapist what level of work the affected limb is actually tolerating, which is essential for graded rehabilitation. Tracking is also useful for monitoring response to medication trials, which often need weeks at a therapeutic dose to assess, and for separating real flares from coincidental bad days⁵.

Pain Coach does not promise a cure. The realistic goal in CRPS is meaningful improvement in pain, function, sleep and quality of life, and for some people, eventual remission of symptoms³. Tracking is what lets you and your clinical team see when meaningful improvement is happening, and adjust treatment when it is not.

The five lifestyle factors and CRPS

Each of the five factors Pain Coach tracks affects CRPS, with some interactions specific to this condition.

• Exercise and movement. Graded movement and sensory input to the affected limb is central to CRPS rehabilitation, but it has to be carefully calibrated to avoid flares^5,3. This is not generic exercise advice. It usually means working with a CRPS-experienced physiotherapist on a structured program that may include graded motor imagery, mirror therapy, desensitisation, and gradual functional use of the limb. General aerobic exercise, for parts of the body unaffected by CRPS, supports overall health and mood¹⁵. Pain Coach shows your physiotherapist what you actually sustained from session to session.
• Sleep. CRPS pain frequently worsens at night and is highly disruptive to sleep, and sleep loss in turn amplifies pain processing^16,17. Tracking sleep alongside pain often reveals how much of the daytime symptom load is downstream of poor sleep, and small improvements in sleep can have outsized effects on how the limb feels.
• Stress. Persistent stress amplifies central pain processing, and CRPS is one of the conditions where central sensitisation has been most clearly demonstrated^18,7. Fear of movement and unhelpful beliefs about pain, particularly the belief that pain means damage, can amplify the experience and slow rehabilitation¹³. Psychological support has consistent evidence as part of multidisciplinary CRPS care, not as a substitute for physical rehabilitation but alongside it¹².
• Social connection. CRPS is often isolating: the condition is rare, invisible to others, and difficult to explain. Isolation and loneliness independently worsen chronic pain outcomes, and social pain shares neural pathways with physical pain^19,20. Connection with others who understand the condition, including the CRPS-specific patient organisations and support groups that exist in Australia, tends to correlate with better days.
• Nutrition. Diet has a smaller but emerging evidence base in chronic musculoskeletal pain more broadly²¹. Regular, balanced eating supports energy, mood and recovery during what is often a long rehabilitation. Pain Coach tracks plant intake, whole-food intake and added sugar so your clinician can see the pattern; it does not prescribe a specific diet.

Find a CRPS-experienced physiotherapist in Australia

Pain Coach Connect lists verified Australian physiotherapists who work with CRPS, with telehealth and in-person consultations available. CRPS rehabilitation is genuinely specialist: graded motor imagery, mirror therapy and the calibration of a safe rehabilitation dose require specific training, and not every physiotherapist works in this area. The listings are filtered to physiotherapists with specific CRPS experience.

Where CRPS is moderate to severe, recently diagnosed, or not responding to first-line care, referral to a pain medicine specialist is usually the appropriate next step alongside physiotherapy. Pain medicine is a distinct specialty in Australia, with pain clinics in most major hospitals and a growing network of pain medicine physicians in private practice. Your GP can refer you.

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