Normal Hair Growth
Hair is an important emblem of health, youth and vitality. Each day the scalp hair grows approximately 0.35 mm. The scalp sheds approximately 100 hairs per day. Each hair follicle passes through 3 phases of growth cycle as the following:
- Anagen or growth phase on the scalp lasts for an average of 3 years. The duration of the anagen phase varies from person to person and it determines how long hair will grow if not cut. At any one time, approximately 85 to 90 percent of scalp follicles are in the anagen phase of growth.
- Catagen phase follows the anagen and is an involutional stage that lasts around 2 weeks. It affects 2 to 3 percent of hair follicles.
- Telogen or dormant phase lasts about 3 months. About 10 to 15 percent of hair follicles undergo a rest period and does not grow. At the end of this phase, the inactive or dead hair is ejected from the skin, leaving a solid, white nodule at its proximal shaft. The cycle is then repeated.
The length of each phase of the cycle and that of the entire cycle, varies with the site and the age of the patient.
Written by: Healthplus24 team
Date last updated: March 24, 2009
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