Educational information, not a treatment plan. This overview is meant to help you understand the condition and prepare informed questions. Diagnosis and treatment decisions should always be made with a qualified healthcare professional. Find a specialist or read our medical disclaimer.
A specific, localized form of amplified pain — usually affecting one limb after an injury — where the nervous system produces severe, persistent pain disproportionate to the original trauma.
Overview
Complex Regional Pain Syndrome (CRPS) is a chronic pain condition that most often affects one limb (arm, leg, hand, or foot) after an injury, surgery, stroke, or sometimes with no clear trigger. It is considered a localized form of AMPS. In CRPS, the nervous system becomes dysregulated, producing pain that is far more severe and persistent than the original injury would suggest. The pain is accompanied by changes in skin color, temperature, sweating, swelling, and sometimes hair and nail growth in the affected limb. CRPS is real and physical — it is not imagined or exaggerated. It can occur at any age, including in children, where outcomes are often better with early functional treatment.
Common Symptoms
Symptoms typically include: continuous, severe burning or throbbing pain in the affected limb; pain from light touch or normal use (allodynia); heightened sensitivity to painful stimuli; swelling; changes in skin color (red, purple, pale, or blotchy); temperature differences between limbs; changes in sweating (more or less); stiffness and reduced range of motion; weakness; and changes in nail or hair growth. Symptoms can spread beyond the original site in some cases. Pain often worsens with stress, temperature changes, or emotional distress, and may fluctuate in intensity.
Diagnosis
CRPS is diagnosed clinically using the Budapest Criteria, which assess symptom patterns including sensory (pain, allodynia), vasomotor (temperature/color changes), sudomotor/edema (swelling, sweating changes), and motor/trophic (stiffness, weakness, hair/nail changes) categories. No single test confirms CRPS, though tests may be used to rule out other conditions. Diagnosis is best made by a pain specialist, neurologist, or physician experienced in chronic pain. Early diagnosis is associated with better outcomes. Because standard imaging may appear normal, patients are sometimes dismissed — finding a knowledgeable provider is essential.
Current Treatments
CRPS treatment is most effective when started early and uses a multidisciplinary, functional-restoration approach. Physical and occupational therapy focus on gradual desensitization, restoring movement and function, and retraining the nervous system — even when painful. Pain psychology helps with coping, stress reduction, and addressing nervous system sensitization. Mirror therapy, graded motor imagery, and desensitization techniques are commonly used. Medications (such as certain anticonvulsants, antidepressants, or topical agents) may help but are usually secondary to functional treatment. In severe cases, intensive rehabilitation programs or, rarely, interventional procedures may be considered. Prolonged immobilization tends to worsen CRPS. Many patients, particularly children and adolescents, improve significantly or recover with appropriate, timely treatment.
Research Summary
CRPS research focuses on central and peripheral nervous system mechanisms, including neuroinflammation, autonomic dysfunction, central sensitization, and maladaptive cortical changes (alterations in how the brain maps the affected limb). The Budapest Criteria have standardized diagnosis. Studies support early, active functional rehabilitation as the most effective intervention. Research into pain neuroscience education, graded motor imagery, and virtual reality-based therapies is ongoing. While outcomes vary, pediatric CRPS generally has better recovery rates than adult-onset CRPS when treated promptly. More research is needed on long-term outcomes, recurrence, and preventing chronicity.
Community Resources
RSDSA (rsds.org): the leading U.S. organization for CRPS support, education, advocacy, and provider referrals. International Research Foundation for RSD/CRPS (rsdfoundation.org). U.S. Pain Foundation (uspainfoundation.org). Burning Nights CRPS Support. Peer support — both online communities and local groups — can be invaluable for reducing isolation and sharing practical coping strategies.
References
1. International Association for the Study of Pain (IASP) — CRPS guidelines and Budapest Criteria. 2. Harden RN et al. Validation of diagnostic criteria for CRPS (Budapest Criteria). Pain Medicine, 2010. 3. RSDSA (rsds.org). 4. National Institute of Neurological Disorders and Stroke (ninds.nih.gov). 5. American Academy of Pain Medicine (painmed.org). Note: this information is educational and not a substitute for professional medical advice.