Reflex Sympathetic Dystrophy

Reflex sympathetic dystrophy (RSD) is a chronic painful disorder of the sympathetic nervous system, a division of the autonomic nervous system (ANS). The ANS is separate from, yet closely associated with, the central nervous system (CNS- the brain and spinal cord) and the peripheral nervous systems (PNS-nerves leading to the extremities). A formal nomenclature devised in 1993 has led to some degree of confusion and a name change to CRPS (complex regional pain syndrome) but most still use the older and more familiar term RSD.