The main BFRB disorders are:

- Skin

- Dermatillomania (excoriation disorder), skin picking

- Dermatophagia, skin nibbling

- Mouth

- Morsicatio buccarum, cheek biting

- Morsicatio labiorum, inner lip biting

- Morsicatio buccarum, tongue biting

- Hands

- Onychophagia, nail biting

- Onychotillomania, nail picking

- Nose

- Rhinotillexomania, compulsive nose picking

- Hair

- Trichophagia, hair nibbling

- Trichotemnomania, hair cutting

- Trichotillomania, hair pulling

Tourette’s syndrome is a neurological disorder characterized by recurrent involuntary movements (motor tics) and involuntary noises (vocal tics). The reason Tourette’s syndrome and other tic disorders are being considered for placement in the obsessive compulsive spectrum is because of the phenomenology and co-morbidity of the disorders with obsessive compulsive disorder. Within the population of patients with OCD up to 40% have a history of a tic disorder and 60% of people with Tourette’s syndrome have obsessions and/or compulsions. Plus 30% of people with Tourette’s syndrome have full-scale OCD. Course of illness is another factor that suggests correlation because it has been found that tics displayed in childhood are a predictor of obsessive and compulsive symptoms in late adolescence and early adulthood. However, the association of Tourette’s and tic disorders with OCD is challenged by neuropsychology and pharmaceutical treatment. Whereas OCD is treated with SSRI’s, tics are treated with dopamine blockers and alpha-2 agonists.

Trichotillomania is defined as a self-induced and recurrent loss of hair. It includes the criterion of an increasing sense of tension before pulling the hair and gratification or relief when pulling the hair. However, some people with trichotillomania do not endorse the inclusion of "rising tension and subsequent pleasure, gratification, or relief" as part of the criteria; because many individuals with trichotillomania may not realize they are pulling their hair, patients presenting for diagnosis may deny the criteria for tension prior to hair pulling or a sense of gratification after hair is pulled.

Trichotillomania may lie on the obsessive-compulsive spectrum, also encompassing obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), nail biting (onychophagia) and skin picking (dermatillomania), tic disorders and eating disorders. These conditions may share clinical features, genetic contributions, and possibly treatment response; however, differences between trichotillomania and OCD are present in symptoms, neural function and cognitive profile. In the sense that it is associated with irresistible urges to perform unwanted repetitive behavior, trichotillomania is akin to some of these conditions, and rates of trichotillomania among relatives of OCD patients is higher than expected by chance. However, differences between the disorder and OCD have been noted, including: differing peak ages at onset, rates of comorbidity, gender differences, and neural dysfunction and cognitive profile. When it occurs in early childhood, it can be regarded as a distinct clinical entity.

Because trichotillomania can be present in multiple age groups, it is helpful in terms of prognosis and treatment to approach three distinct subgroups by age: preschool age children, preadolescents to young adults, and adults.

Trichotillomania is often not a focused act, but rather hair pulling occurs in a "trance-like" state; hence, trichotillomania is subdivided into "automatic" versus "focused" hair pulling. Children are more often in the automatic, or unconscious, subtype and may not consciously remember pulling their hair. Other individuals may have focused, or conscious, rituals associated with hair pulling, including seeking specific types of hairs to pull, pulling until the hair feels "just right", or pulling in response to a specific sensation. Knowledge of the subtype is helpful in determining treatment strategies.

Body dysmorphic disorder is defined by an obsession with an imagined defect in physical appearance, and compulsive rituals in an attempt to conceal the perceived defect. Typical complaints include perceived facial flaws, perceived deformities of body parts and body size abnormalities. Some compulsive behaviors observed include mirror checking, ritualized application of makeup to hide the perceived flaw, excessive hair combing or cutting, excessive physician visits and plastic surgery. Body dysmorphic disorder is not gender specific and onset usually occurs in teens and young adults.

Trichotillomania is usually confined to one or two sites, but can involve multiple sites. The scalp is the most common pulling site, followed by the eyebrows, eyelashes, face, arms, and legs. Some less common areas include the pubic area, underarms, beard, and chest. The classic presentation is the "Friar Tuck" form of vertex and crown alopecia. Children are less likely to pull from areas other than the scalp.

People who suffer from trichotillomania often pull only one hair at a time and these hair-pulling episodes can last for hours at a time. Trichotillomania can go into remission-like states where the individual may not experience the urge to "pull" for days, weeks, months, and even years.

Individuals with trichotillomania exhibit hair of differing lengths; some are broken hairs with blunt ends, some new growth with tapered ends, some broken mid-shaft, or some uneven stubble. Scaling on the scalp is not present, overall hair density is normal, and a hair pull test is negative (the hair does not pull out easily). Hair is often pulled out leaving an unusual shape. Individuals with trichotillomania may be secretive or shameful of the hair pulling behavior.

An additional psychological effect can be low self-esteem, often associated with being shunned by peers and the fear of socializing, due to appearance and negative attention they may receive. Some people with trichotillomania wear hats, wigs, false eyelashes, eyebrow pencil, or style their hair in an effort to avoid such attention. There seems to be a strong stress-related component. In low-stress environments, some exhibit no symptoms (known as "pulling") whatsoever. This "pulling" often resumes upon leaving this environment. Some individuals with trichotillomania may feel they are the only person with this problem due to low rates of reporting.

For some people, trichotillomania is a mild problem, merely a frustration. But for many, shame and embarrassment about hair pulling causes painful isolation and results in a great deal of emotional distress, placing them at risk for a co-occurring psychiatric disorder, such as a mood or anxiety disorder. Hair pulling can lead to great tension and strained relationships with family members and friends. Family members may need professional help in coping with this problem.

Other medical complications include infection, permanent loss of hair, repetitive stress injury, carpal tunnel syndrome, and gastrointestinal obstruction as a result of trichophagia. In trichophagia, people with trichotillomania also ingest the hair that they pull; in extreme (and rare) cases this can lead to a hair ball (trichobezoar). Rapunzel syndrome, an extreme form of trichobezoar in which the "tail" of the hair ball extends into the intestines, can be fatal if misdiagnosed.

Environment is a large factor which affects hair pulling. Sedentary activities such as being in a relaxed environment are conducive to hair pulling. A common example of a sedentary activity promoting hair pulling is lying in a bed while trying to rest or fall asleep. An extreme example of automatic trichotillomania is found when some patients have been observed to pull their hair out while asleep. This is called sleep-isolated trichotillomania.

Body-focused repetitive behavior (BFRB) is an umbrella name for impulse control behaviors involving compulsively damaging one's physical appearance or causing physical injury.

Body-focused repetitive behavior disorders (BFRBDs) in ICD-11 is in development.

BFRB disorders are not generally considered obsessive-compulsive disorders.

Intermittent explosive disorder or IED is a clinical condition of experiencing recurrent aggressive episodes that are out of proportion of any given stressor. Earlier studies reported a prevalence rate between 1%-2% in a clinical setting, however a study done by Coccaro and colleagues in 2004 had reported about 11.1% lifetime prevalence and 3.2% one month prevalence in a sample of a moderate number of individuals (n=253). Based on the study, Coccaro and colleagues estimated the prevalence of IED in 1.4 million individuals in the US and 10 million with lifetime IED.

Compulsive shopping or buying is characterized by a frequent irresistible urge to shop even if the purchases are not needed or cannot be afforded. The prevalence of compulsive buying in the U.S. has been estimated to be 2–8% of the general adult population, with 80–95% of these cases being females. The onset is believed to occur in late teens or early twenties and the disorder is considered to be generally chronic.

Trichophagia is characterized by the person eating hair, usually their own; primarily after pulling it out. Most often, hair is pulled out and then the ends of the root bulb are eaten, or occasionally the hair shaft itself. The hair eventually collects in the gastrointestinal tract (on occasion, and depending upon severity of symptoms) causing indigestion and stomach pain. Ritual is a strong factor, and may involve touching the root bulb to the lips, tasting the hair, and occasionally chewing it. Sometimes those with the disorder may even eat the hair of others. In the psychiatric field it is considered a compulsive psychological disorder.

Self-harm (SH), also referred to as "self-injury" (SI), "self-inflicted violence" (SIV), "nonsuicidal self injury" (NSSI) or "self-injurious behaviour" (SIB), refers to a spectrum of behaviours where demonstrable injury is self-inflicted. The behaviour involves deliberate tissue damage that is usually performed without suicidal intent. The most common form of self-harm involves cutting of the skin using a sharp object, e. g. a knife or razor blade. The term "self-mutilation" is also sometimes used, although this phrase evokes connotations that some find worrisome, inaccurate, or offensive. "Self-inflicted wounds" is a specific term associated with soldiers to describe non-lethal injuries inflicted in order to obtain early dismissal from combat. This differs from the common definition of self-harm, as damage is inflicted for a specific secondary purpose. A broader definition of self-harm might also include those who inflict harm on their bodies by means of disordered eating.

Nonsuicidal self injury has been listed as a new disorder in the DSM-5 under the category "Conditions for Further Study". This disorder occurs when a person is deliberately harming themselves in a physical way without the intent of committing suicide. Self-harm without suicidal intent can be seen on a spectrum, just like many other disorders (substance abuse, gambling addiction). Just like these other disorders, once the self harming behaviours cross a certain threshold, it then becomes classified as a mental health disorder. Criteria for NSSI include five or more days of self-inflicted harm over the course of one year without suicidal intent, and the individual must have been motivated by seeking relief from a negative state, resolving an interpersonal difficulty, or achieving a positive state.

A common belief regarding self-harm is that it is an attention-seeking behaviour; however, in many cases, this is inaccurate. Many self-harmers are very self-conscious of their wounds and scars and feel guilty about their behaviour, leading them to go to great lengths to conceal their behaviour from others. They may offer alternative explanations for their injuries, or conceal their scars with clothing. Self-harm in such individuals may not be associated with suicidal or para-suicidal behaviour. People who self-harm are not usually seeking to end their own life; it has been suggested instead that they are using self-harm as a coping mechanism to relieve emotional pain or discomfort or as an attempt to communicate distress. Alternatively, interpretations based on the supposed lethality of a self-harm may not give clear indications as to its intent: life risking behaviour may have no suicidal intent, whilst seemingly superficial cuts may have been a suicide attempt.

Studies of individuals with developmental disabilities (such as intellectual disability) have shown self-harm being dependent on environmental factors such as obtaining attention or escape from demands. Some individuals may have dissociation harboring a desire to feel real or to fit into society's rules.

Eighty percent of self-harm involves stabbing or cutting the skin with a sharp object. However, the number of self-harm methods are only limited by an individual's inventiveness and their determination to harm themselves; this includes burning, self-poisoning, alcohol abuse, self-embedding of objects, hair pulling, bruising/hitting one's self, scratching to hurt one's self, knowingly abusing over the counter or prescription drugs, and forms of self-harm related to anorexia and bulimia. The locations of self-harm are often areas of the body that are easily hidden and concealed from the detection of others. As well as defining self-harm in terms of the act of damaging the body, it may be more accurate to define self-harm in terms of the intent, and the emotional distress that the person is attempting to deal with. Neither the DSM-IV-TR nor the ICD-10 provide diagnostic criteria for self-harm. It is often seen as only a symptom of an underlying disorder, though many people who self-harm would like this to be addressed.

Common signs that a person may be engaging in self harm include the following: they ensure that are always harmful objects close by, they are experiencing difficulties in their personal relationships, their behaviour becomes unpredictable, they question their worth and identity, they make statements that display helplessness and hopelessness.

Trichophagia () is the compulsive eating of hair associated with trichotillomania (hair pulling). In trichophagia, people with trichotillomania also ingest the hair that they pull; in extreme (and rare) cases this can lead to a hair ball (trichobezoar).

Causes include:

- Schizophrenia

- Bipolar disorder

- Excited delirium

- Post-traumatic stress disorder (PTSD)

- Panic attacks

- Anxiety disorder

- Obsessive-compulsive disorder (OCD)

- Alcohol withdrawal

- Claustrophobia

- Dementia

- Parkinson's disease

- Traumatic brain injury

- Alzheimer's disease

- Acute intermittent porphyria

- Hereditary coproporphyria

- Variegate porphyria

- Side effects of drugs like cocaine or methylphenidate

- Side effects of antipsychotics like haloperidol

In considering whether an individual has thought disorder, patterns of their speech are closely observed. Although it is normal to exhibit some of the following during times of extreme stress (e.g. a cataclysmic event or the middle of a war) it is the degree, frequency, and the resulting functional impairment that leads to the conclusion that the person being observed has a thought disorder.

- "Alogia" (also "poverty of speech") – A poverty of speech, either in amount or content; it can occur as a negative symptom of schizophrenia.

- "Blocking" – An abrupt stop in the middle of a train of thought; the individual may or may not be able to continue the idea. This is a type of formal thought disorder that can be seen in schizophrenia.

- "Circumstantiality" (also "circumstantial thinking", or "circumstantial speech") – An inability to answer a question without giving excessive, unnecessary detail. This differs from tangential thinking, in that the person does eventually return to the original point.

- "Clanging" or "Clang association" – a severe form of flight of ideas whereby ideas are related only by similar or rhyming sounds rather than actual meaning. This may be heard as excessive rhyming and/or alliteration. e.g. "Many moldy mushrooms merge out of the mildewy mud on Mondays." "I heard the bell. Well, hell, then I fell." It is most commonly seen in bipolar affective disorder (manic phase), although it is often observed in patients with primary psychoses, namely schizophrenia and schizoaffective disorder.

- "Derailment" (also "loose association" and "knight's move thinking") – Thought and/or speech move, either spontaneously or in response to an internal stimulus (distinguishing derailment from "distractible speech," "infra"), from the topic's track onto another which is obliquely related or unrelated. e.g. "The next day when I'd be going out you know, I took control, like uh, I put bleach on my hair in California."

- "Distractible speech" – During mid speech, the subject is changed in response to an external stimulus. e.g. "Then I left San Francisco and moved to... where did you get that tie?"

- "Echolalia" – Echoing of another's speech that may only be committed once, or may be continuous in repetition. This may involve repeating only the last few words or last word of the examiner's sentences. This can be a symptom of Tourette's Syndrome. e.g. "What would you like for dinner?", "That's a good question. "That's a good question". "That's a good question". "That's a good question"."

- "Evasive interaction" – Attempts to express ideas and/or feelings about another individual come out as evasive or in a diluted form, e.g.: "I... er ah... you are uh... I think you have... uh-- acceptable erm... uh... hair."

- "Flight of ideas" – a form of formal thought disorder marked by abrupt leaps from one topic to another, albeit with discernable links between successive ideas, perhaps governed by similarities between subjects or, in somewhat higher grades, by rhyming, puns, and word plays (clang associations), or innocuous environmental stimuli – e.g., the sound of birds chirping. It is most characteristic of the manic phase of bipolar illness.

- "Illogicality" – Conclusions are reached that do not follow logically (non-sequiturs or faulty inferences). e.g. "Do you think this will fit in the box?" draws a reply like "Well duh; it's brown, isn't it?"

- "Incoherence (word salad)" – Speech that is unintelligible because, though the individual words are real words, the manner in which they are strung together results in incoherent gibberish, e.g. the question "Why do people comb their hair?" elicits a response like "Because it makes a twirl in life, my box is broken help me blue elephant. Isn't lettuce brave? I like electrons, hello please!"

- "Loss of goal" – Failure to follow a train of thought to a natural conclusion. e.g. "Why does my computer keep crashing?", "Well, you live in a stucco house, so the pair of scissors needs to be in another drawer."

- "Neologisms" – New word formations. These may also involve elisions of two words that are similar in meaning or in sound. e.g. "I got so angry I picked up a dish and threw it at the geshinker."

- "Perseveration" – Persistent repetition of words or ideas even when another person attempts to change the topic. e.g. "It's great to be here in Nevada, Nevada, Nevada, Nevada, Nevada." This may also involve repeatedly giving the same answer to different questions. e.g. "Is your name Mary?" "Yes." "Are you in the hospital?" "Yes." "Are you a table?" "Yes." Perseveration can include palilalia and logoclonia, and can be an indication of organic brain disease such as Parkinson's.

- "Phonemic paraphasia" – Mispronunciation; syllables out of sequence. e.g. "I slipped on the lice and broke my arm."

- "Pressure of speech" – Unrelenting, rapid speech without pauses. It may be difficult to interrupt the speaker, and the speaker may continue speaking even when a direct question is asked.

- "Self-reference" – Patient repeatedly and inappropriately refers back to self. e.g. "What's the time?", "It's 7 o'clock. That's my problem."

- "Semantic paraphasia" – Substitution of inappropriate word. e.g. "I slipped on the coat, on the ice I mean, and broke my book."

- "Stilted speech" – Speech characterized by the use of words or phrases that are flowery, excessive, and pompous. e.g. "The attorney comported himself indecorously."

- "Tangentiality" – Wandering from the topic and never returning to it or providing the information requested. e.g. in answer to the question "Where are you from?", a response "My dog is from England. They have good fish and chips there. Fish breathe through gills."

- "Word approximations" – Old words used in a new and unconventional way. e.g. "His boss was a ."

Thought disorder (TD) or formal thought disorder (FTD) refers to disorganized thinking as evidenced by disorganized speech. Specific thought disorders include derailment, poverty of speech, tangentiality, illogicality, perseveration, and thought blocking.

Psychiatrists consider formal thought disorder as being one of two types of disordered thinking, with the other type being delusions. The latter involves "content" while the former involves "form". Although the term "thought disorder" can refer to either type, in common parlance it refers most often to a disorder of thought "form" also known as formal thought disorder.

Eugen Bleuler, who named schizophrenia, held that thought disorder was its defining characteristic. However, formal thought disorder is not unique to schizophrenia or psychosis. It is often a symptom of mania, and less often it can be present in other mental disorders such as depression. Clanging or echolalia may be present in Tourette syndrome. Patients with a clouded consciousness, like that found in delirium, also have a formal thought disorder.

However, there is a clinical difference between these two groups. Those with schizophrenia or psychosis are less likely to demonstrate awareness or concern about the disordered thinking. Clayton and Winokur have suggested that this results from a fundamental inability to use the same type of Aristotelian logic as others. On the other hand, patients with a clouded consciousness, referred to as "organic" patients, usually do demonstrate awareness and concern, and complain about being "confused" or "unable to think straight"; Clayton and Winokur suggest that this is because their thought disorder results, instead, from various cognitive deficits.

Psychomotor agitation is a set of signs and symptoms that stem from mental tension and anxiety. The signs are unintentional and purposeless motions; the symptoms are emotional distress and restlessness. Typical manifestations include pacing around a room, wringing the hands, uncontrolled tongue movement, pulling off clothing and putting it back on, and other similar actions. In more severe cases, the motions may become harmful to the individual, such as ripping, tearing, or chewing at the skin around one's fingernails, lips, or other body parts to the point of bleeding. Psychomotor agitation is typically found in major depressive disorder or obsessive-compulsive disorder, and sometimes the manic phase in bipolar disorder, though it can also be a result of an excess intake of stimulants. It can also be caused by severe hyponatremia. The middle-aged and the elderly are more at risk to express it.

Feather-plucking is generally regarded as a multifactorial disorder, although three main aspects of bird keeping may be related to the problem: (1) cage size often restricts the bird’s movements; (2) cage design and barrenness of the environment often do not provide sufficient behavioural opportunities to meet the bird's sensitivity, intelligence and behavioural needs; and (3) solitary housing, which fails to meet the high social needs of the bird.

Many medical causes underlying the development of feather-plucking have been proposed including allergies (contact/inhalation/food), endoparasites, ectoparasites, skin irritation (e.g. by toxic substances, low humidity levels), skin desiccation, hypothyroidism, obesity, pain, reproductive disease, systemic illness (in particular liver and renal disease), hypocalcaemia, psittacine beak and feather disease (PBFD), proventricular dilatation syndrome, colic, giardiasis, psittacosis, airsacculitis, heavy metal toxicosis, bacterial or fungal folliculitis, genetic feather abnormalities, nutritional deficiencies (in particular vitamin A) and/or dietary imbalances, and neoplasia. For many of the above-mentioned factors, a causative relationship or correlation has not been established and may therefore merely be the result of coincidental findings.

Approximately 50% of parrots exhibiting feather damaging behaviour have been diagnosed as having inflammatory skin disease based on paired skin and feather biopsies. The birds try to relieve itching by grooming their feathers, but this often leads to over-grooming and eventually feather-plucking.

The presentation may be of alopecia (baldness). Individuals vary in severity of symptoms. Nail deformities may also be present as well as hair follicle keratosis and follicular hyperkeratosis.

Among the symptoms(and signs) for this condition are the following:

- lack of apparent hair growth

- hair appears patchy

- hair breaks easily close to scalp

- hair may have thickenings or nodes in the shaft

- ends of hair thinned or split

- whitish discoloration of hair tips

- hair breaks easily at tips

Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase (the resting phase of the hair follicle). Emotional or physiological stress may result in an alteration of the normal hair cycle and cause the disorder, with potential causes including eating disorders, fever, childbirth, chronic illness, major surgery, anemia, severe emotional disorders, crash diets, hypothyroidism, and drugs.

Diagnostic tests, which may be performed to verify the diagnosis, include a trichogram, trichoscopy and biopsy. Effluvium can present with similar appearance to alopecia totalis, with further distinction by clinical course, microscopic examination of plucked follicles, or biopsy of the scalp. Histology would show telogen hair follicles in the dermis with minimal inflammation in effluvium, and dense peribulbar lymphocytic infiltrate in alopecia totalis.

Vitamin D levels may also play a role in normal hair cycle.

Trichorrhexis nodosa is a defect in the hair shaft characterized by thickening or weak points (nodes) that cause the hair to break off easily. This group of conditions contributes to the appearance of hair loss, lack of growth, and damaged-looking hair.

Hair is one of the defining characteristics of mammals. In humans, hair can be scalp hair, facial hair, chest hair, pubic hair, axillary hair, besides other places. Men tend to have hair in more places than women. Hair does not in itself have any intrinsic sexual value other than the attributes given to it by individuals in a cultural context. Some cultures are ambivalent in relation to body hair, with some being regarded as attractive while others being regarded as unaesthetic. Many cultures regard a woman's hair to be erotic. For example, many Islamic women cover their hair in public, and display it only to their family and close friends. Similarly, many Jewish women cover their hair after marriage. During the Middle Ages, European women were expected to cover their hair after they married.

Even in cultures where women do not customarily cover their hair, the erotic significance of hair is recognised. Some hair styles are culturally associated with a particular gender, with short head hair styles and baldness being associated with men and longer hair styles with women and girls, even though there are many exceptions such as Gaelic Irish men, and also depictions of men in art throughout history, the most notable example probably being that of Jesus Christ. In the case of women especially, head hair has been presented in art and literature as a feature of beauty, vanity and eroticism. Hair has a very important role in the canons of beauty in different regions of the world, and healthy combed hair has two important functions, beauty and fashion. In those cultures considerable time and expense is put into the attractive presentation of hair, and in some cases to the removal of culturally unwanted hair.

Hair fetishism manifests itself in a variety of behaviors. A fetishist may enjoy seeing or touching hair, pulling on or cutting the hair of another person. Besides enjoyment they may become sexually aroused from such activities. It may also be described as an obsession, as in the case of hair washing or dread of losing hair. Arousal by head hair may arise from seeing or touching very long or short hair, wet hair, a certain color of hair or a particular hairstyle. Others may find the attraction of literally "having sex with somebody's hair" as a fantasy or fetish. The fetish affects both men and women.

Some people feel pleasure when their hair is being cut or groomed. This is because they produce endorphins giving them a feeling which is similar to that of a head massage, laughter, or caress. On the other hand, many people feel some level of anxiety when their head hair is being cut. Sigmund Freud stated that cutting woman's long hair by men may represent a fear and/or concept of castration, meaning that a woman's long hair represents a figurative penis and that by cutting off her hair a man may feel dominance as castrator, not the castrated one (while paradoxically also being reassured by the fact that the hair will grow again).

Trichophilia may present with different excitation sources, the most common, but not the only one, being human head hair. Trichophilia may also involve facial hair, chest hair, pubic hair, armpit hair and animal fur. The excitation can arise from the texture, color, hairstyle and hair length. Among the most common variants of this paraphilia are excitation by long hair and short hair, the excitement of blonde hair (blonde fetishism) and red hair (redhead fetishism) and the excitement of the different textures of hair (straight, curly, wavy, etc.). Trichophilia can relate to the excitement that is caused by plucking or pulling hair or body hair.

Hair fetishism comes from a natural fascination with the species on the admiration of the coat, as its texture provides pleasurable sensations. An infant develops this kind of pleasure to feel the hair on his or her early life, manifesting as aggressive behavior that will drive to pull the hair of people with which it interacts. Trichophilia is considered a paraphilia which is usually inoffensive.

Hair abnormalities are very prominent in majority of the cases of TDO. Kinky/curly hair that is unusually dry and easily sheds is present at birth. In 80% of cases, the hair has a more relaxed appearance by adolescence. The presence of this hair texture type is a defining characteristic between a diagnosis of TDO verses amelogenesis imperfecta with hypomaturation. Additionally, in TDO the nails are usually abnormally thin, brittle, and split frequently. Cranial deficiencies are marked by the presence of having a long skull relative to its width, or protrusive foreheads due to increased thickness of the cranial bones and premature closing of the associated sutures in the skull. The long bones in the body (arms, legs) are also abnormally long and tend to fracture very easily. Osteosclerosis, commonly seen in TDO cases is characterized by an increase in bone density, affecting the skull and the mastoid process located behind the jawbone on the skull, as well as a shortened ramus seen in people with TDO. There are no known pathological problems associated with hair and bone changes in people with this disease. Changes in the long bones tend to appear later in development, but changes in the teeth appear once the teeth being to form, called primary dentition. The hair and bone abnormalities are evaluated radiographically during initial diagnosis, and visually during the course of the disease. Radiographic exams may be repeated if there is suspect of fracture.

Traction alopecia is a form of alopecia, or gradual hair loss, caused primarily by pulling force being applied to the hair. This commonly results from the sufferer frequently wearing their hair in a particularly tight ponytail, pigtails, or braids. It is also seen occasionally in long-haired people who use barrettes to keep hair out of their faces. Traction alopecia is recession of the hairline due to chronic traction, or hair pulling, and is characterized by a fringe along the marginal hairline on physical exam. Even though this "fringe sign" is considered a useful clinical marker of this condition, cases of frontal fibrosing alopecia presenting with an unusual retention of the hairline (pseudo-fringe sign) have been described.