Tardive Dyskinesia (TD) is a serious and often irreversible movement disorder that can occur as a side effect of long-term use of antipsychotic medications. These medications are commonly used to treat psychiatric conditions such as schizophrenia and bipolar disorder, as well as other mental health issues. TD is characterized by repetitive, involuntary movements, particularly of the face, lips, and tongue, but it can also affect other parts of the body.