Coprolalia encompasses words and phrases that are culturally taboo or generally unsuitable for acceptable social use, when used out of context. The term is not used to describe contextual swearing. It is usually expressed out of social or emotional context, and may be spoken in a louder tone or different cadence or pitch than normal conversation. It can be a single word, or complex phrases. A person with coprolalia may repeat the word mentally rather than saying it out loud; these subvocalizations can be very distressing.

Coprolalia is an occasional characteristic of Tourette syndrome, although it is not required for a diagnosis of Tourette's. In Tourette syndrome, compulsive swearing can be uncontrollable and undesired by the person uttering the phrases. Involuntary outbursts, such as racial or ethnic slurs in the company of those most offended by such remarks, can be particularly embarrassing. The phrases uttered by a person with coprolalia do not necessarily reflect the thoughts or opinions of the person.

Cases of deaf Tourette patients swearing in sign language have been described, showing that coprolalia is not just a consequence of the short and sudden sound pattern of many swear words.

Coprolalia is involuntary swearing or the involuntary utterance of obscene words or socially inappropriate and derogatory remarks. Coprolalia comes from the Greek κόπρος ("kopros") meaning "feces" and λαλιά ("lalia") from "lalein", "to talk".

Coprolalia is an occasional characteristic of tic disorders, in particular Tourette syndrome, although it is not required for a diagnosis of Tourette's, and only about 10% of Tourette's patients exhibit coprolalia. It is not unique to tic disorders; it is also a rare symptom of other neurological disorders.

Related involuntary actions are copropraxia, performing obscene or forbidden gestures, and coprographia, making obscene writings or drawings.

Tics are movements or sounds "that occur intermittently and unpredictably out of a background of normal motor activity", having the appearance of "normal behaviors gone wrong". The tics associated with Tourette's change in number, frequency, severity and anatomical location. Waxing and waning—the ongoing increase and decrease in severity and frequency of tics—occurs differently in each individual. Tics may also occur in "bouts of bouts", which vary for each person.

Coprolalia (the spontaneous utterance of socially objectionable or taboo words or phrases) is the most publicized symptom of Tourette's, but it is not required for a diagnosis of Tourette's and only about 10% of Tourette's patients exhibit it. Echolalia (repeating the words of others) and palilalia (repeating one's own words) occur in a minority of cases, while the most common initial motor and vocal tics are, respectively, eye blinking and throat clearing.

In contrast to the abnormal movements of other movement disorders (for example, choreas, dystonias, myoclonus, and dyskinesias), the tics of Tourette's are temporarily suppressible, nonrhythmic, and often preceded by an unwanted premonitory urge. Immediately preceding tic onset, most individuals with Tourette's are aware of an urge, similar to the need to sneeze or scratch an itch. Individuals describe the need to tic as a buildup of tension, pressure, or energy which they consciously choose to release, as if they "had to do it" to relieve the sensation or until it feels "just right". Examples of the premonitory urge are the feeling of having something in one's throat, or a localized discomfort in the shoulders, leading to the need to clear one's throat or shrug the shoulders. The actual tic may be felt as relieving this tension or sensation, similar to scratching an itch. Another example is blinking to relieve an uncomfortable sensation in the eye. These urges and sensations, preceding the expression of the movement or vocalization as a tic, are referred to as "premonitory sensory phenomena" or premonitory urges. Because of the urges that precede them, tics are described as semi-voluntary or ""unvoluntary"", rather than specifically "involuntary"; they may be experienced as a "voluntary", suppressible response to the unwanted premonitory urge. Published descriptions of the tics of Tourette's identify sensory phenomena as the core symptom of the syndrome, even though they are not included in the diagnostic criteria.

While individuals with tics are sometimes able to suppress their tics for limited periods of time, doing so often results in tension or mental exhaustion. People with Tourette's may seek a secluded spot to release their symptoms, or there may be a marked increase in tics after a period of suppression at school or at work. 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. They may have tics for several years before becoming aware of premonitory urges. Children may suppress tics while in the doctor's office, so they may need to be observed while they are not aware they are being watched. The ability to suppress tics varies among individuals, and may be more developed in adults than children.

Although there is no such thing as a "typical" case of Tourette syndrome, the condition follows a fairly reliable course in terms of the age of onset and the history of the severity of symptoms. Tics may appear up to the age of eighteen, but the most typical age of onset is from five to seven. A 1998 study published by Leckman and colleagues from the Yale Child Study Center showed that the ages of highest tic severity are eight to twelve (average ten), with tics steadily declining for most patients as they pass through adolescence. The most common, first-presenting tics are eye blinking, facial movements, sniffing and throat clearing. Initial tics present most frequently in midline body regions where there are many muscles, usually the head, neck and facial region. 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.

Most cases of Tourette's in older individuals are mild and almost unrecognizable. When symptoms are severe enough to warrant referral to clinics, obsessive–compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD) are often associated with Tourette's. In children with tics, the additional presence of ADHD is associated with functional impairment, disruptive behavior, and tic severity. Compulsions resembling tics are present in some individuals with OCD; "tic-related OCD" is hypothesized to be a subgroup of OCD, distinguished from non-tic related OCD by the type and nature of obsessions and compulsions. Not all persons with Tourette's have ADHD or OCD or other comorbid conditions, although in clinical populations, a high percentage of patients presenting for care do have ADHD. One author reports that a ten-year overview of patient records revealed about 40% of patients with Tourette's have "TS-only" or "pure TS", referring to Tourette syndrome in the absence of ADHD, OCD and other disorders. Another author reports that 57% of 656 patients presenting with tic disorders had uncomplicated tics, while 43% had tics plus comorbid conditions. People with "full-blown Tourette's" have significant comorbid conditions in addition to tics.

Tics are sudden, repetitive, nonrhythmic movements (motor tics) and utterances (phonic tics) that involve discrete muscle groups. Motor tics are movement-based tics, while phonic tics are involuntary sounds produced by moving air through the nose, mouth, or throat.

Tourette's was classified by the fourth version of the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-IV-TR) as one of several tic disorders "usually first diagnosed in infancy, childhood, or adolescence" according to type (motor or phonic tics) and duration (transient or chronic). Transient tic disorders consisted of multiple motor tics, phonic tics or both, with a duration between four weeks and twelve months. Chronic tic disorder was either single or multiple, motor or phonic tics (but not both), which were present for more than a year. Tourette's is diagnosed when multiple motor tics, and at least one phonic tic, are present for more than a year. The fifth version of the DSM (DSM-5), published in May 2013, reclassified Tourette's and tic disorders as motor disorders listed in the neurodevelopmental disorder category, and replaced transient tic disorder with provisional tic disorder, but made few other significant changes.

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].

Although Tourette's is the more severe expression of the spectrum of tic disorders, most cases are mild. The severity of symptoms varies widely among people with Tourette's, and mild cases may be undetected.

Palilalia is considered an aphasia, a disorder of language, and is not to be confused with speech disorders, as there is no difficulty in the formation of internal speech. Palilalia is similar to speech disorders such as stuttering or cluttering, as it tends to only express itself in spontaneous speech, such as answering basic questions, and not in automatic speech such as reading or singing; however, it distinctively affects words and phrases rather than syllables and sounds.

Palilalia may occur in conditions affecting the pre-frontal cortex or basal ganglia regions, either from physical trauma, neurodegenerative disorders, genetic disorders, or a loss of dopamine in these brain regions. Palilalia occurs most commonly in Tourette syndrome and may be present in neurodegenerative disorders like Alzheimer's disease and progressive supranuclear palsy.

Palilalia (from the Greek πάλιν ("pálin") meaning "again" and λαλιά ("laliá") meaning "speech" or "to talk"), a complex tic, is a language disorder characterized by the involuntary repetition of syllables, words, or phrases. It has features resembling other complex tics such as echolalia or coprolalia, but, unlike other aphasias, palilalia is based upon contextually correct speech.

It was originally described by Alexandre-Achille Souques in a patient with stroke that resulted in left-side hemiplegia, although a condition described as auto-echolalia in 1899 by Édouard Brissaud may have been the same condition.

Copropraxia is a tic consisting of involuntarily performing obscene or forbidden gestures, or inappropriate touching. Copropraxia comes from the Greek "κόπρος" meaning "feces" and "πράξις" meaning "action". Copropraxia is a rare characteristic of Tourette syndrome.

Related terms are coprolalia, referring to involuntary usage of profane words, and coprographia, making vulgar writings or drawings.

Coprographia is involuntarily making vulgar writings or drawings. Coprographia comes from the Greek "κόπρος" meaning "feces" and "graphia" meaning to write.

Related terms are coprolalia, the involuntary usage of scatalogical words, and copropraxia, the involuntary performance of obscene gestures.

Persons affected are cognitively impaired and have behavioral disturbances that emerge between two and three years of age. The uncontrollable self-injury associated with LNS also usually begins at three years of age. The self-injury begins with biting of the lips and tongue; as the disease progresses, affected individuals frequently develop finger biting and head banging. The self-injury can increase during times of stress. Self-harm is a distinguishing characteristic of the disease and is apparent in 85% of affected males.

The majority of individuals are cognitively impaired, which is sometimes difficult to distinguish from other symptoms because of the behavioral disturbances and motor deficits associated with the syndrome. In many ways, the behaviors may be seen as a psychological extension of the compulsion to cause self-injury, and include rejecting desired treats or travel, repaying kindness with coldness or rage, failing to answer test questions correctly despite study and a desire to succeed, provoking anger from caregivers when affection is desired.

Compulsive behaviors also occur, including aggressiveness, vomiting, spitting, and coprolalia (involuntary swearing). The development of this type of behavior is sometimes seen within the first year, or in early childhood, but others may not develop it until later in life.

The periods before and surrounding birth are typically normal in individuals with LNS. The most common presenting features are abnormally decreased muscle tone (hypotonia) and developmental delay, which are evident by three to six months of age. Affected individuals are late in sitting up, while most never crawl or walk. Lack of speech is also a very common trait associated with LNS.

Irritability is most often noticed along with the first signs of nervous system impairment. Within the first few years of life, extrapyramidal involvement causes abnormal involuntary muscle contractions such as loss of motor control (dystonia), writhing motions (choreoathetosis), and arching of the spine (opisthotonus). Signs of pyramidal system involvement, including spasticity, overactive reflexes (hyperreflexia) and extensor plantar reflexes, also occur. The resemblance to athetoid cerebral palsy is apparent in the neurologic aspects of LNS. As a result, most individuals are initially diagnosed as having cerebral palsy. The motor disability is so extensive that most individuals never walk, and become lifelong wheelchair users.