Review of current medical literature reveals little understanding of the physiology underlying the complex signs and symptoms that accompany reflex sympathetic dystrophy (RSD). The author surveyed the osteopathic medical literature and found a significant body of research documenting the physiology of somatic dysfunction. The manifestations of upper thoracic somatic dysfunction are strikingly similar to those of RSD and may offer insight into its heretofore unexplained physiology of this disorder.