How CRPS Is Diagnosed
A Plain-English Guide to the Budapest Criteria
TL;DR
Complex Regional Pain Syndrome (CRPS) is diagnosed clinically—there’s no single blood test. The Budapest Criteria ask: (1) Do you have ongoing pain out of proportion to any injury? (2) Do you report symptoms in 3 of 4 categories? (3) Can a clinician find signs in 2 of 4 categories on exam today? (4) Is there no better diagnosis? Early recognition helps.
What is CRPS—and why “Budapest” matters
CRPS is a chronic pain condition where nerves, blood vessels, and immune signaling seem to misfire after an injury, surgery, immobilization—or sometimes with no obvious trigger. The Budapest Criteria are the current best-validated checklist for diagnosis. They improve accuracy compared with older rules and help avoid both over- and under-diagnosis.
The four categories, in plain English
You first need continuing pain out of proportion to the original injury/trigger.
Then clinicians consider 4 symptom/sign categories.
You report symptoms in ≥3 of 4 categories, and the clinician finds at least one sign in ≥2 of 4 categories during the exam.
Sensory
Symptoms: burning, pins/needles, touch feels painful (allodynia), “too much” pain from a painful stimulus (hyperalgesia)
Signs (exam): pain to light touch/brush/pinprick compared with the other side
Vasomotor (color & temperature)
Symptoms: the limb looks red/blue or feels warmer/colder
Signs (exam): visible color asymmetry, measurable temp difference vs the other side
Sudomotor/Edema (sweat & swelling)
Symptoms: swelling, sweating changes, or obvious side-to-side differences
Signs (exam): pitting edema, sweat asymmetry, shiny/mottled appearance
Motor/Trophic (movement & tissue changes)
Symptoms: stiffness, weakness, tremor/dystonia, clumsy movement, changes to hair/skin/nails
Signs (exam): limited range of motion, visible dystonia/tremor, brittle nails, thin/shiny skin, altered hair growth
Rule-outs: No other diagnosis should better explain the picture (e.g., untreated infection, compartment syndrome, acute vascular issue).
CRPS I vs CRPS II
CRPS I: no confirmed nerve injury
CRPS II: there is a confirmed nerve injury on testing
The Budapest checklist applies to both.
Pediatric note (kids & teens)
Clinicians often adapt the adult Budapest Criteria in pediatrics. Evidence suggests we need better child-specific tools, so clinical judgment is key. If it sounds like CRPS in a child/teen, seek a clinician with pediatric pain experience.
References
Harden RN, Bruehl S, Perez RSGM, et al. Validation of proposed diagnostic criteria (the “Budapest Criteria”) for Complex Regional Pain Syndrome. Pain. 2010;150(2):268-274. doi:10.1016/j.pain.2010.04.030. URL: https://journals.lww.com/pain/fulltext/2010/08000/validation_of_proposed_diagnostic_criteria__the.14.aspx
Used for: The validated structure of the Budapest Criteria and their superior diagnostic accuracy vs prior IASP rules.Faculty of Pain Medicine (Royal College of Anaesthetists). Criteria for diagnosis (Budapest Criteria). 2021. URL: https://fpm.ac.uk/documents/criteria-diagnosis
Used for: Exact clinician-facing wording—symptoms in ≥3/4 categories and signs in ≥2/4 categories, plus rule-out language.Lloyd ECO, Kumar V. Complex Regional Pain Syndrome. Am Fam Physician. 2021;104(1):49-58. URL: https://www.aafp.org/pubs/afp/issues/2021/0700/p49.html
Used for: Performance estimates in adults (high sensitivity ~99% and moderate specificity ~68%) to set expectations about diagnostic accuracy.Misidou C, Papagoras C. Complex regional pain syndrome: An update. Rheumatol Int. 2019;39(12):1853-1863. URL: https://pmc.ncbi.nlm.nih.gov/articles/PMC7045919/
Used for: Practical summary of symptom/sign categories and note that a proportion of patients report no obvious inciting event.Harden RN, Bruehl S, Perez RSGM, et al. Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th ed. Pain Med. 2022;23(Suppl 1):S1-S53. doi:10.1093/pm/pnab343. URL: https://academic.oup.com/painmedicine/article/23/Supplement_1/S1/6605306
Used for: Current guideline context for applying Budapest criteria and integrating them into a treatment pathway.Mesaroli G, Hundert A, Birnie KA, et al. Screening and diagnostic tools for complex regional pain syndrome: a systematic review. Pain. 2021;162(5):1295-1304. doi:10.1097/j.pain.0000000000002146. URL: https://journals.lww.com/pain/fulltext/2021/05000/screening_and_diagnostic_tools_for_complex.4.aspx
Used for: Emphasis that pediatric-validated tools are lacking; clinicians often extrapolate adult Budapest criteria in youth.Tham SW, Shah K, Asaro C, et al. Application of diagnostic criteria in paediatric complex regional pain syndrome: a scoping review protocol. BMJ Open. 2025;15:e095057. URL: https://pmc.ncbi.nlm.nih.gov/articles/PMC12086909/
Used for: Reinforcing the research gap in pediatric-specific diagnostic criteria and the need for clinician judgment in children/teens.