Chorea (sometimes called Choreia) is the name for a set of symptoms caused by some neurological conditions. The word "chorea" comes from Greek, where it means "dance". People with chorea move without being able to control those movements. The movements seem to spread from one muscle to the next.
Chorea is one of the main symptoms of Huntington's disease.
Some forms of chorea are not linked to neurological conditions, though. Chorea can develop as a complication of pregnancy. It can be a sign of hyperthyroidism. It can also be caused by drugs taken in the wrong dose. For example, L-Dopa (taken against Parkinson's disease), certain forms of birth control, or certain antipsychotics can cause chorea if they are used in the wrong doses.