The hair life cycle
Hair has cycles of growth and resting. The normal process of the hair life cycle is referred to as hair renewal. The average daily hair loss is 60-80 hairs, in spring and autumn this can get up to around 100 hairs per day.
 
 
 
The development of hair
Of the 80,000-140,000 hairs on a head, approx. 90 % are in the growth phase, 1-3 % is in the transition phase and 12-18 % are in the rest phase. Hair growth depends on genes and hormones. Hair on the head generally grows much faster than hair on other parts of the body. This is because the hair bulbs in the head are particularly active.
* The average growth of a hair is 0.35 mm/day.

Anagen phase (active growing phase)
During this phase the hair follicle produces a hair; it is in the active growing phase. The growth rate of an anagen hair is approx. 1 cm/month. This means for a head of 80,000 hairs 25-30 metres of hair grow daily or approx. 800 meters in a month. Around 90 % of the hair on a head is in this stage. The duration of the anagen phase is 2-6 years. If the hair matrix suffers mild damage during the anagen phase, it will move prematurely from the growth to the transitory phase, thereby shortening the hair life cycle.

Catagen phase (transitionary phase)
After the growth phase there is a change of processes in the hair follicle. The hair matrix regresses, the external walls of the follicle close above the papilla forming an epithelial column. This surrounds the base of the club hair and slowly pushes it towards the skin’s surface.

Telogen phase (resting phase)
A club of completely horny cells forms at the bottom of the hair shaft. This club hair rises in the follicle canal until it is just below where the sebaceous gland meets the hair shaft. Within 2-4 months this firm capsule gets thinner and thinner and the grip of the club hair in the follicle canal gets increasingly looser. The telogen hair leaves the scalp either by mechanical means such as brushing, combing or washing, or it is pushed out of the follicle canal by the new hair of the next cycle. During the resting phase the hair shaft is already completely horny, hence the description “resting phase”. With the help of a light microscopic hair investigation; the trichogram (Tricho Scan process), it is possible to ascertain how many hairs are in the anagen, catagen and telogen phases. The trichogram gives valuable information about the course of the hair life cycle. A hair life cycle of normal speed can thus be differentiated from a faster one.
 
The hair life cycle