Complex regional pain syndrome
Complex regional pain syndrome (CRPS), sometimes referred to by the hyponyms reflex sympathetic dystrophy (RSD) or reflex neurovascular dystrophy (RND) (type 1) or causalgia (type 2), is a rare and severe form of neuroinflammatory and dysautonomic disorder causing chronic pain, neurovascular, and neuropathic symptoms. Although it can vary widely, the classic presentation occurs when severe pain from a physical trauma or neurotropic viral infection outlasts the expected recovery time, and may subsequently spread to uninjured areas.
Source: Wikipedia — Complex regional pain syndrome (CC BY-SA 4.0)