Like HowStuffWorks on Facebook!

Top 10 Rare Diseases

Tardive Dyskinesia

Tardive Dyskinesia (TD) is an involuntary neurological movement disorder caused by the use of dopamine receptor blocking drugs that are prescribed to treat certain psychiatric or gastrointestinal conditions. Long-term use of these drugs may produce biochemical abnormalities in the area of the brain known as the striatum. The reasons that some people who take these drugs may get tardive dyskinesia, and some people do not, is unknown. Tardive dystonia is a more severe form of tardive dyskinesia in which slower twisting movements of the neck and trunk muscles are prominent.