The hair life cycle includes three main phases: anagen, catagen, and telogen, which occur over several years.
1. Anagen phase (growth phase): This phase lasts between 2 and 7 years and determines hair length. Hair grows on average about 1 cm per month during this period.
2. Catagen phase (transition phase): This phase lasts about 10 days. During this period, the hair stops growing and detaches from the hair follicle.
3. Telogen phase (resting phase): This phase lasts about 3 months. The hair remains in place but no longer grows. At the end of this phase, the hair falls out and a new hair begins to grow from the follicle, marking the start of a new cycle.
The duration of these phases varies among individuals and can be influenced by many factors, including age, genetics, and various environmental factors. On average, a person loses between 50 and 100 hairs per day as part of the natural cycle.