Many individuals with Tourette's go undiagnosed or never seek medical care.Among those who are seen in specialty clinics, attention-deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD) are present at higher rates.Because of the urges that precede them, tics are described as semi-voluntary or "unvoluntary", Some people with Tourette's may not be aware of the premonitory urge.Children may be less aware of the premonitory urge associated with tics than are adults, but their awareness tends to increase with maturity.Tourette's is defined as part of a spectrum of tic disorders, which includes provisional, transient and persistent (chronic) tics.While the exact cause is unknown, it is believed to involve a combination of genetic and environmental factors.These co-occurring diagnoses often cause more impairment to the individual than the tics; hence, it is important to correctly identify associated conditions and treat them.
Tics also occur in "bouts of bouts", which vary for each person.
This can be contrasted with the stereotyped movements of other disorders (such as stims and stereotypies of the autism spectrum disorders), which typically have an earlier age of onset, are more symmetrical, rhythmical and bilateral, and involve the extremities (e.g., flapping the hands).
Tics that appear early in the course of the condition are frequently confused with other conditions, such as allergies, asthma, and vision problems: pediatricians, allergists and ophthalmologists are typically the first to see a child with tics.
Tic disorders are defined only slightly differently by the World Health Organization International Statistical Classification of Diseases and Related Health Problems, ICD-10; code F95.2 is for combined vocal and multiple motor tic disorder [de la Tourette].
The tics associated with Tourette's change in number, frequency, severity and anatomical location.
The most common, first-presenting tics are eye blinking, facial movements, sniffing and throat clearing.