The lifecycle of a typical hair follicle is divided into 3 parts :-
- Anagen
- Catagen
- Telogen
Anagen
This stage last 1.5 - 7 Years.It is that stage that is responsible for active growth
of the Hair follicle. Due to the constant division of cells in the dermal papilla,
the older cells are pushed outwards towards the surface of the epidermis. As this process
continues the older cells, which are dead, become keratinised.On an average 85% of
follicles are in the anagen stage.
Catagen
This stage that lasts for only 2 weeks and is the end of the active growth period. The hair
stops growing and becomes detached from the base of the follicle. Although the follicle becomes
shorter and the inner root sheath disintegrates the hair do not fall out due to its shape. On an
average 1% of follicles are in this stage.
Telogen
The last stage or the resting stage before regrowth. This lasts for 3-4 months. In the telogen
stage a new hair grows from the remainder of the root sheath which is in contact with the dermal
papilla. Although the shortened hair shaft is still in the follicle a new anagen stage can take
place, hence sometimes we see two hair follicles through the same pore.
