A tic is a sudden, rapid, recurring, non-rhythmic movement or vocalization.
They can be simple (if they last less than a second), or complex (if they last more than a second). Although they are perceived as involuntary, they can be suppressed voluntarily for short periods of time.
Examples of vocal tics would be: throat clearing, grunting, repetition of words…
Motor tics would be: blinking the eyes, movements of the neck, of the shoulders… In this category we distinguish, from greater to lesser symptomatic intensity:
Tourette’s disorder: implies the existence of both motor and vocal tics for a minimum period of one year, although they do not necessarily have to happen at the same time, nor be the same tics. In fact, it is common for a subject to present several different tics over time, which may disappear and reappear later.
Persistent motor or vocal tic disorder: it is similar to Tourette’s, but in this case there is only one type of tic: either motor or vocal.
When the period of duration of the tics is less than a year, it is referred to as transient tic disorder.