About CRPS

Complex Regional Pain Syndrome is, as its name suggests, complex!

​In its most simplest explanation, it is continuing pain out of proportion to the severity and normal time frame of the event that caused the initial pain. As well as pain it involves sensory, autonomic, motor and/or tropic symptoms.

CRPS Type 1 arises from a variety of risk factors, most commonly trauma such as fractures and soft tissue injuries. CRPS Type 1 is the most common. (It was previously referred to as Reflex Sympathetic Dystrophy (RSD) and Sudeck’s atrophy).

CRPS Type 2 is associated with nerve injury. (It was previously referred to as causalgia).


People with CRPS experience some or all of the following in their affected limb:

  • persistent pain which can be severe
  • burning or freezing sensations
  • swelling
  • hypersensitivity to touch
  • joint stiffness
  • skin colour changes (may appear red, mottled, or cyanosed, or all at different times)
  • increased sweating
  • changes to the skin, nails, and hair
  • muscle weakness and spasms.

The emotional impact of CRPS can lead to distress, anxiety and depression.


Under the Budapest Criteria, to make a clinical diagnosis all four of the following must be met:

  1. Continuing pain which is disproportionate to any inciting event
  2. Must report at least one symptom in three of the four following categories
    • Sensory: reports of hyperaesthesia
    • Vasomotor: reports of temperature asymmetry and/or skin colour changes and/or skin colour asymmetry
    • Sudomotor/Oedema: reports of oedema (swelling) and/or sweating changes and/or sweating asymmetry
    • Motor/Trophic: reports of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
  3. Must display at least one sign at time of evaluation in two or more of the following categories
    • Sensory: evidence of hyperalgesia (to pinprick) and/or allodynia (to light touch and/or temperature sensation and/or deep somatic pressure and/or joint movement)
    • Vasomotor: evidence of temperature asymmetry (>1 oC) and/or skin colour changes and/or asymmetry
    • Sudomotor/Oedema: evidence of oedema (swelling) and/or sweating changes and/or sweating asymmetry
    • Motor/Trophic: evidence of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
  4. There is no other diagnosis that better explains the signs and symptoms.

Dimensions of pain

This diagram is a visual representation of some of the categories and words that individuals can use to describe the quality and intensity of their pain. The McGill Pain Questionnaire was developed by Melzack and Torgerson (Melzack, 1975).


Complex regional pain syndrome is complicated to treat. Treatment is more likely to be successful if it starts early after CRPS has manifested, ideally within the first six months. Unfortunately CRPS often goes undiagnosed because its symptoms can be mistaken as that of other conditions and medical professionals often do not recognise it.

CRPS requires a multidisciplinary team approach to treatment. Following is a list of some of the treatments that people with CRPS may be given:

  • information & education
  • medication
  • physiotherapy
  • pain psychology
  • pacing, breathing, relaxation techniques
  • graded motor imagery
  • mirror therapy
  • hydrotherapy
  • occupational therapy.

There is no proven cure for CRPS. The aim of these interventions is to reduce pain, increase functionality, and improve quality of life.

Understanding CRPS

video spotlight – MAy-June 2024
Past video spotlights


  • Melzack, R. (1975). The McGill Pain Questionnaire: Major properties and scoring methods. Pain 1(3), 277-299. https://doi.org/10.1016/0304-3959(75)90044-5
  • Royal College of Physicians. (2018). Complex regional pain syndrome in adults. (2nd ed.). https://www.rcplondon.ac.uk/guidelines-policy/complex-regional-pain-syndrome-adults