CRPS is a chronic pain condition that causes extreme pain, swelling, and changes in skin color and temperature in the affected area. It is classified into two types depending on the presence of nerve injury. Symptoms progress through three stages as the condition worsens over time without treatment. Diagnosis involves assessing signs and symptoms, and may include bone scans, x-rays, and thermography. Treatment requires a multidisciplinary approach including medications, nerve blocks, physical therapy, spinal cord stimulators, or sympathectomy to interrupt the pain cycle. Early diagnosis and treatment improves prognosis.