The main symptoms of tic disorders in children are: motor or/and vocal tics, sensory tics and behavioral problems. 1. Motor tics: Motor tics are involuntary, sudden, rapid contractions of the muscles of the head, face, neck, shoulders, trunk and limbs. It is classified into simple and complex motor tics according to the range, characteristics and severity of the muscle groups involved. Simple motor tics are sudden, brief, repetitive, purposeless movements, usually involving one or several smaller muscle groups, often in bursts and in isolated individual forms, such as blinking, shrugging, head shaking, eye rolling up, or nasal fluttering. Complex motor twitching is a purposeful act of performing a random action, a coordinated continuous action, such as touching the nose, touching others, as if sniffing, jumping, obscene behavior (abhorrent behavior), and imitation. Alternatively, purposeless complex twitching may include head shaking, shoulder shrugging, repeated leg kicking and various facial movements. Vocal twitches: Vocal twitches are twitches involving respiratory muscles, pharyngeal muscles, laryngeal muscles, oral muscles and nasal muscles, where the muscles contract to produce vocalizations through the airflow of the nose, mouth and throat. Simple vocal tics are often characterized by repeated animal-like grunting, throat clearing, roaring, and nasal aspiration. Complex vocal tics are often characterized by repeated sounds of meaningful words, such as obscenities, imitation language or repetitive language. 3. Sensory twitching: Self-complained local discomfort before motor or vocal twitching is called sensory twitching. Such as a feeling of pressure, itching, heat, cold, etc. or a feeling of impulsiveness or anxiety. Motor twitching occurs to relieve discomfort in the affected somatic area, and vocal twitching occurs to relieve discomfort in the throat. Sensory twitching can be seen as a precursor symptom of motor or vocal twitching. 4. Behavioral problems: Children with tic disorders often have psycho-behavioral co-morbidities. For example, obsessive-compulsive disorder (OCD), including obsessive-compulsive ideas or compulsive behaviors or both; attention deficit hyperactivity disorder (ADHD), learning difficulties (LD), sleep disorders (SD), self-injurious behavior, destructive behavior (DB), mood disorders (ED), molestation, etc.