Trichotillomania (TTM), or "trich" as it is commonly known, is an impulse control disorder characterized by the repeated urge to pull out scalp hair, eyelashes, beard hair, nose hair, eyebrows or other body hair. It may be distantly related to obsessive-compulsive disorder, with which it shares some similarities. The number of reported trichotillomania sufferers has increased throughout the years, possibly due to a reduced stigmatism around the condition. The number of reported sufferers is currently estimated to be 1% or 2% of the population.
Trichotillomania has been mentioned as a disorder in very early historical records. For many there seems to be a strong stress-related component, that is, in low-stress environments some sufferers exhibit no symptoms, known as 'pulling', whatsoever. This 'pulling' often resumes upon leaving this environment.[citation needed]
65% of those afflicted are female
Evidence now points to a genetic predisposition.
Most TTM sufferers live relatively normal lives, except for having bald spots on their head, among their eyelashes, pubic hair, or brows. Eyelashes have been reported to grow back thinner or in much lesser amounts.
An additional danger is from the low self-esteem associated with being shunned by peers, and the fear of socializing due to appearance.
Many clinicians classify TTM as a habitual behavior, in the same family as nail biting (onychophagia) or compulsive skin picking (dermatotillomania). These disorders are a cross between mental disorders, such as OCD obsessive compulsive disorder because the sight or feel of a body part causes the sufferer anxiety, and physical disorders such as Stereotypic Movement Disorder because the sufferer performs repetitive movements without being bothered by or completely aware of them. Many TTM sufferers have normal work and social lives; and TTM sufferers are not any more likely to have significant personality disorders than anyone else.[citation needed] Sufferers may also eat the roots of the hair. It is characteristic that they may feel they are the only person with this problem due to low rates of self reportage.
While there is no cure, there are some treatments. Early trichotillomania sufferers were treated using electro-shock therapy. Although this eventually fell out of favor. There have been a few small and not well-controlled clinical trials of drug treatment for trichotillomania, for example using such drugs as anafranil, prozac, and lithium. There have also been anecdotal reports of vitamin therapy being successful.[citation needed] No one medication has been shown to have a particular advantage over any other, and drugs alone have not been shown to be particularly effective for many people. One should use care in choosing a therapist who has specific training, experience, and insight into the condition, lest one be overdiagnosed or overmedicated. Prozac and other similar drugs, which some professionals prescribe on a one-size-fits-all basis, tend to have limited usefulness in treating TTM, and can often have significant side effects.
Patients should be cautioned that treatment of comorbid conditions such as Attention Deficit Hyperactivity Disorder with stimulants may increase the frequency and intensity of hair-pulling.
A practice related to TTM is trichophagia, in which hairs are swallowed. In extreme cases, this can lead to the development of a hairball (trichobezoar) in the abdomen, a serious condition in humans; see Rapunzel syndrome. A trichobezoar can lead to intestinal blockage, which may only be relieved via surgery

Info Source, Links, and more info:
http://en.wikipedia.org/wiki/Trichotillomania