Tics are spasm-like movements of particular muscles in the body. There are two types of tics: motor and vocal. Motor tics are short-lasting movements and vocal tics are uttered sounds; both may occur suddenly during what is otherwise classified as normal behavior. Tics can be either simple or complex.
- Motor-eye blinking, nose-twitching, head jerking, shoulder shrugging, and facial grimacing
- Vocal-throat clearing, yelping, and other noises, sniffing and tongue clicking
- Motor-jumping, touching other people or things, smelling, twirling about, and only rarely, self-injurious actions including hitting or biting oneself; usually a series of movements performed in the same order
- Vocal-uttering words or phrases out of context and coprolalia (vocalizing socially unacceptable words).
Doctors use the following four characteristics to identify and diagnose tic disorders:
- The age when tics began
- Duration of the tics
- Severity of the tics, and
- Whether tics are motor or vocal or both