complex regional pain syndrome

Short definition from Wiktionary

Noun

1. 1
   A chronic systemic disease characterized by severe pain, swelling, changes in the skin (e.g., erythema, edema), functional impairment, and sensory and vasomotor disturbance. Often it initially affects an arm or leg before spreading through the body; it is associated with dysregulation of the central nervous system and autonomic nervous system.