Tics are fast, repetitive muscle movements that result in sudden and difficult to control body jolts or sounds. They can be classified into two types: motor tics and vocal tics. Motor tics are involuntary movements caused by spasm-like contractions of muscles, most commonly involving the face, mouth, eyes, head, neck, or shoulders. Vocal tics, on the other hand, are sudden, short sounds or utterances that are made involuntarily. Tics are often repetitive, with numerous successive occurrences of the same action. They tend to get worse if they are talked about or focused on. Tics can happen randomly and they may be associated with something such as stress, anxiety, tiredness, excitement, or happiness. They can also be triggered by taking certain medications.

The exact cause of tics is not known, but they are thought to be due to changes in the parts of the brain that control movement. Tics can run in families, and theres likely to be a genetic cause in many cases. Stress and sleep deprivation seem to play a role in both the occurrence and severity of motor tics. In some cases, tics can be a symptom of Tourette Syndrome, which is a condition of the nervous system. It is a complex disorder likely caused by a combination of inherited (genetic) and environmental factors. It has been found that tics are primarily caused by abnormalities in the GABAergic striatal networks, leading to an excess of striatal dopamine.

If tics occur very regularly, or become more frequent or severe, cause emotional or social problems, such as embarrassment, bullying or social isolation, cause pain or discomfort, interfere with daily activities, school or work, or are accompanied by anger, depression or self-harm, it is recommended to seek medical attention.