This document discusses Sudeck's osteodystrophy, also known as complex regional pain syndrome (CRPS). It defines CRPS as a chronic progressive disease characterized by disproportionate regional pain and abnormalities in sensory, motor, and autonomic nervous system function. It describes three stages of CRPS based on dystrophic and atrophic changes. Treatment involves prevention, non-operative approaches like physical therapy, nerve stimulation, nerve blockade, and in some cases surgical sympathectomy. The goal is to reduce pain and limit progression of the chronic condition.