Tourette’s syndrome is a condition that affects a person's central nervous system and causes tics. Tics are movements or sounds that a person can't control and that are repeated over and over.

People with Tourette syndrome have both motor tics and vocal tics. Motor tics are movements of the muscles a person can't control, and they include eye blinking, head shaking, jerking of the arms, and shrugging. Vocal tics are sounds that a person with Tourette syndrome makes with his or her voice and can't control. Throat clearing, grunting, and coughing are all common vocal tics. 

A person with Tourette syndrome sometimes has more than one type of tic happening at once. Tics can happen throughout the day. But tics often happen less or go away completely when a person is concentrating (like working on a computer) or relaxing (like listening to music).

The type of tics often change over time. How often the tics happen often changes, too. Tics are usually worse when a person is under stress (like when studying for a big test) or excited or very energized about something (like at a birthday party or a sports activity). Tics can even happen when a person first falls asleep, but usually slow down and disappear completely during the deeper stages of sleep.