Chorea (or choreia, occasionally) is an abnormal involuntary movement disorder, one of a group of neurological disorders called dyskinesias. The term chorea is derived from the Greek word χορεία (=dance; see choreia), as the quick movements of the feet or hands are comparable to dancing.The term hemichorea refers to chorea of one side of the body, such as chorea of one arm but not both (analogous to hemiballismus).