Hair growth
Human hair goes through three phases as part of its healthy growth: The growth phase, followed by the so-called transition phase and a resting phase. Hair usually falls out after 2 to 6 years. The so-called hair shaft and the ends of the hair form the visible part of the hair. The hair root, in turn, is located under the scalp. It is surrounded by the hair follicle, in which hair growth is regulated.
Growth phase (anagen phase)
By dividing the so-called matrix cells, the hair papilla ensures the formation of new hair, which grows by up to 0.3 mm per day. This growth phase lasts 2 to 6 years. During this period, the hair grows approximately 1 cm per month. This phase is characterized by a high rate of cell division and high metabolic activity. Around 85% of hair is in the growth phase.
Transition phase (catagen phase)
The completed growth phase is followed by the so-called transition phase, which lasts 1 to 2 weeks. Hair growth and the metabolic activity of the matrix cells are terminated in this phase.
Resting phase (telogen phase)
The hair, which is now completely separated from the root, is no longer supplied with nutrients. However, the hair follicle becomes active again at the end of the resting phase and begins to produce new hair. In this way, the old hair is displaced, so to speak, until it finally falls out. This phase can last up to 5 months. Approximately 15 % of the hair on the head is in the resting phase. The ratio of anagen hair to telogen hair is around 10:1. The daily loss of telogen hair is normally between 50 and 100 hairs.