Delayed dyskinesia is divided into the following types according to the site of dyskinesia ① abnormal eye muscle movement: blinking, blepharospasm, etc.; ② abnormal facial muscle movement: facial muscle twitching, jerking and sad face, etc.; ③ abnormal mouth muscle movement: pouting, smacking, chewing, suction and lateral jaw movement, etc.; ④ abnormal tongue muscle movement: tongue extension, tongue contraction, wriggling and lip licking, etc.; ⑤ abnormal pharyngeal muscle movement: abnormal palate movement affecting pronunciation and (6) abnormal neck movement: slanting neck, backward neck, etc.; (7) abnormal trunk movement: uncoordinated trunk movement, odd posture, such as shrugging shoulders and retracting back, corkscrew, twisting spasm, diaphragm spasm producing grunting and breathing difficulties, sometimes the whole body swaying from side to side, repeated trunk flexion and extension, back and forth twisting, called body shaking sign; (8) abnormal limb movement: continuous flexion and extension of the distal limbs, called playing piano fingers (toes) sign. The proximal end is rarely involved, and a few of them show dance-like finger paddling movements, throwing movements, hand and foot squirming-like movements, repeatedly raising the hands or jumping on both legs. How to diagnose tardive dyskinesia? It occurs mostly in elderly patients, especially in women, with organic brain lesions, with severe symptoms and slow recovery. It can be caused by various antipsychotics, and is common with fluoride-containing antipsychotics such as fluphenazine, trifluoperazine and haloperidol, and mostly occurs after taking antipsychotics for more than 1 to 2 years, with a minimum of 3 to 6 months and a maximum of 13 years. The main clinical manifestations are rhythmic stereotyped repetitive involuntary movements, early manifestations of tongue tremor or salivation, characteristic mouth movements in the elderly, and common limb involvement in younger patients. In children, the orofacial symptoms are more prominent, and the lower muscles are most often involved, showing the mouth-tongue-buccal triad (BLM syndrome) or cheek, tongue and mastication syndrome, showing repetitive and uncontrollable movements of the lips and tongue, such as involuntary continuous stereotyped chewing, sucking, tongue turning, tongue licking, pouting and cheek puffing, crooked jaw and neck turning, sometimes the tongue suddenly sticks out of the mouth involuntarily, called flytrap tongue sign, and in severe cases, slurred diction In severe cases, there is slurred speech and swallowing disorder. The involvement of trunk muscles shows body shaking, the involvement of distal limbs shows piano finger (toe) sign, the proximal limbs are rarely involved, a few show dance-like movements, aimless flapping, legs jumping, hand and foot twitching, twisting trunk movements and odd postures. Occasionally, the gastrointestinal tract is affected, with stomach discomfort, nausea and vomiting occurring after sudden discontinuation of the drug. The symptoms are aggravated by emotional stress and excitement and disappear during sleep. Some patients have co-existence with delayed sedentary inability, delayed dystonia, and pharmacogenic Parkinson’s syndrome, and the symptoms are easily masked and exposed when the medication is reduced or discontinued. Antipsychotics can cause acute idiopathic dystonia or acute sedentary inability, mostly within 2 days of antipsychotic use and easily occurring in children and early adulthood, manifesting dramatic twitching or uncomfortable postures of the limbs, trunk, neck, tongue, and facial muscles. Subtypes of TD: (1) acute withdrawal syndrome: involuntary fluttering non-repetitive choreographic movements occur when antipsychotic drugs are suddenly stopped, similar to microdance or Hontington’s disease, mostly in children, and can resolve spontaneously; gradual reduction of dosage can lead to gradual disappearance of choreographic movements; (2) delayed dystonia: can occur in both children and adults, with involuntary movements similar to torsional dystonia or torsional spasms, persisting The presence of involuntary movements is similar to torsional dystonia or torsional spasm, which persists without showing rapid repetitive stereotyped movements. According to the patient’s history of taking antipsychotic drugs or long-term use of antidepressants, antiparkinsonian drugs, antiepileptic drugs or antihistamines, dyskinesia occurs during the course of medication or within 3 months after stopping medication, showing rhythmic repetitive and persistent involuntary movements.