Patients with tic disorders have uncontrollable urges to make sudden, rapid and repetitive movements and/or sounds. These movements and vocalizations are expelled as a response to the intolerable urge (also known as premonitory urge) often coming from a muscle group. Premonitory urges are like the urge to sneeze, yawn or scratch an itch. The frequency of tics may be affected by stress and changes in emotions.