Researchers estimate that 1-2% of the U.S. population has trichotillomania - a compulsion to repetitively pull or pluck one’s hair, resulting in noticeable hair loss. Many people with trichotillomania feel ashamed and embarrassed by their hair pulling, attempt to hide it from friends, co-workers and family members, and do not seek help. Many who consult their personal physician or a dermatologist because of hair loss never reveal the true cause and doctors often fail to consider this diagnosis. Although trichotillomania can begin in very young children or middle-aged adults, the most common age of onset is during early adolescence. Women seem to be affected more than men with some estimates suggesting a ratio of 3 women to every man.

Trichotillomania is currently categorized as an impulse control disorder in which the urge to pull hair is associated with an increasing sense of tension. The act of pulling itself is presumed to relieve that tension. Trichotillomania has been considered a habit, like nail biting, that can have both a soothing function and potential consequences.

While the actual cause of trichotillomania is not known for certain, several factors appear to play contributing roles:

• Yeast infection. Some consider trichotillomania to be an allergic reaction to the Mallesezia-yeast and that certain foods encourage growth of this yeast in the body. This causes an urge with some people to pull out their own hair. Professor John Kender from Columbia University tried a diet which changed his life dramatically, as well as the lives of hundreds of others with trichotillomania.
• Metabolic abnormalities. Alterations in brain metabolism seem to be involved. Investigators found differences in neuropsychological testing and in special brain scans between people with trichotillomania and people who do not pull out hair. There is some suggestion that abnormalities in the functioning of serotonin, a chemical neurotransmitter in the brain, might be involved. Interestingly, several medications that have shown promise in trichotillomania increase the amount of serotonin available to brain cells.
• Stress. The onset of trichotillomania is sometimes associated with a stressful event and, indeed, stressful life experiences may be important in its development or its continuation. Stressors may include school conflict, abuse, family conflict, threatened loss of a significant other, severe medical illness, or previous scalp trauma or surgery. More often than not, a significant life event cannot be identified that is related to the onset of trichotillomania.
• Family history. There may be some genetic predisposal ion to developing trichotillomania. Relatives of people with the condition have a slightly increased likelihood of developing trichotillomania compared to the general population. In addition, relatives of people with trichotillomania may have a higher prevalence of other psychiatric disorders, particularly depression and obsessive compulsive disorder, than the population at large.
• Unresolved psychological conflicts-- Psychoanalysts have suggested that pulling out hair is related to erotic wishes or unresolved life conflicts, or that hair pulling releases unsatisfied sexual tension or substitutes for masturbation. Other theories have suggested that hair pulling is an aggressive reaction against feelings of grief or rage or even against feelings of being deserted or unloved. While all of these ideas are interesting, they are unproven, speculative and have no treatment utility.

Some experts feel that trichotillomania is a variant of obsessive compulsive disorder. Both conditions are characterized by compulsive behavior that is usually recognized as senseless, is difficult to resist, and is associated with anxiety. Also, treatment with medications that have similar effects on serotonin, a brain neurotransmitter, may benefit both trichotillomania and OCD. In addition, OCD is more common in people with trichotillomania than in the general population. Furthermore, the observation that a higher than expected number of relatives of trichotillomania sufferers have obsessive compulsive disorder suggests a genetic link between the two disorders.

On the other hand, in contrast to OCD, people with trichotillomania tend not to have obsessive thoughts, do not engage in rituals other than hair pulling, and have a different pattern of abnormal brain metabolism. Also, trichotillomania patients are more likely to be women while OCD has a more even gender distribution. Consequently, the relationship of trichotillomania to OCD is not fully understood; currently they are thought to be related but distinct disorders.

Most people with the condition experience anxiety; embarrassment, and diminished self-confidence and self-esteem. Attempts to keep the condition a secret can lead to avoidance of everyday activities such as visits to the hairdresser, sports, exercise, dancing, public showers, swimming, and being in brightly lit rooms. Some avoid treatment for medical or dental problems because of concern that their hair pulling will be discovered. Many go to great lengths to conceal their hair pulling and try to camouflage hair loss with different hair styles, make-up, clothing, or wigs or other hair pieces.

Hair pulling very rarely causes irreversible baldness. However, when the behavior stops, hair occasionally grows back gray or white and it may be finer, coarser, or curlier. These changes may normalize over time. While hair pulling is going on, scalp inflammation, irritation, itchiness, and tenderness are common. The trauma of hair pulling also increases the risk for scalp infection. Sometimes repetitive hair pulling can cause problems such as carpal tunnel syndrome, tendonitis, and neck/back strain. Perhaps the most common serious medical complication of trichotillomania is avoiding medical care for other illnesses because of the shame associated with hair pulling and the fear of its discovery.

Some researchers have found that nearly 20% of hair pullers eat their hair or chew off and swallow the root ends. Called trichophagy, it can lead to hair being lodged between the teeth and more seriously to large accumulations of retained hairs in the stomach and digestive tract called trichobezoars (hairballs).

Symptoms of trichobezoars include abdominal pain, nausea, vomiting, and sometimes blood and/or visible hairs in the stool. Trichobezoars can also cause foul breath, poor appetite, constipation, diarrhea, excessive gas, bowel obstruction, and even bowel perforation. Liver and pancreas functions can be adversely altered. Sometimes a physician can feel a trichobezoar by gently pushing in the mid or left upper area of a patient's abdomen. Trichobezoars can be diagnosed by using special upper gastrointestinal x-rays, looking into the stomach with an endoscope, or using ultrasound. Surgical removal is the most common treatment.

Some researchers have described early onset (childhood) and later onset (adolescence) types of trichotillomania. There is no clear evidence that children with this form of the disorder are at increased risk for developing future psychiatric problems. However, children who are four, five or six and are still pulling their hair may begin to overlap with the later onset type trichotillomania which has a less favorable prognosis.