Male pattern baldness is a typical pattern of hair loss in men that is caused by genetics and hormones. Approximately 95 percent of all men who suffer some degree of hair loss do so because of male pattern baldness otherwise known as androgenetic alopecia.
Hair Growth Phases
1) Anagen
Growth Phase - Approximately 85 percent of the hair on your head is in the growing phase at any given time. This phase can last 2 to 6 years. Hair can grown at the rate of approximately 5 inches per year and any individual hair is unlikely to grow more than one yard long.
2) Catagen
Transitional phase. When the Anagen growth phase comes to an end, hair enters into a Catagen phase which lasts about one or two weeks. During this transitional phase, the hair follicle shrinks to about 1/6th of the normal diameter. The "root" is diminished and the dermal papilla breaks away and rests below the scalp.
3) Telogen
Resting Phase. After the catagen phase, hair goes into a resting phase known as telogen. This period can last five to six weeks. Although the hair does not grown during this stage, the dermal papilla stays in resting phase below the scalp. Approximately 10 to 15 percent of all hairs on your head are in this resting phase at any given moment. At the end of this stage, the hair follicle re-enters the growth phase. The dermal papilla and the base of the follicle join together again and a new hair begins to form. In some cases, the new hair will push the old hair out of the way and the hair growth cycle starts all over again.
Stress Disorders Leading to Hair Loss?
Trichotillomania, a psychological disorder that may be linked to stress, involves the compulsive pulling or twisting of hair, resulting in patchy or diffuse hair loss. This compulsion is thought to affect as much as 4 percent of the population, and it seems to affect females four times more often than males. This compulsion generally manifests itself before the age of 17 and is often limited to a period of a year or so. The earlier this compulsion appears and the sooner it is treated, the better the prognosis. Trichotillomania is not well understood, and some medical professionals believe that it is simply an ingrained bad habit, but it is sometimes treated with therapy and antidepressants.
