About 10,000 hair roots (hair follicles) on hairy skin consistently grow and lose hair. Humans are born with a certain number of follicles and no new follicle develop throughout life. The process of hair growth and loss occurs in three phases: anagen (growth), catagen (cessation), and telogen (rest). For healthy individuals, about 85%–90%, 10%–15%, and 1% of the hairs are in the growth (anagen), cessation (catagen), and rest (telogen) phases, respectively.
The process starts with new hair production in follicles and lasts until hair is shed. Under normal conditions, baldness is not observedbecause the hair follicle cycle does not occur simultaneously in all follicles. However, a malfunction in the biological rhythm of hair follicles can cause hair loss and thinning. Normal hair fall in adults is approximately 40–100 hairs per day and can be 200–300 hairs when the hair is washed. If more than 100 hairs fall per day ina normal day, it means that a person suffers from hair loss problem.
Hair loss related to hair formation cycle disorders is observed according to the phase that is affected: telogen or anagen effluvium. Women mostly experience hair loss in reproductive periods. Telogen effluvium (TE) is the reason for hair loss mostly encountered in female patients. Alopecia areata and androgenetic alopecia (male-type hair loss seen in women) are a consequence of TE.