Each cell, each cell of hair, has a life time. Often these cells are reproduced by the body, but sometimes it happens that they are not reproduced. This is the same case for the hair cells.
Each strand of hair, each hair root cells have a life cycle. This life cycle is composed of three periods. The life cycle is divided into three sections, the anagen period, the telogen period and kategen period at the end of three periods, the life cycle take end and end with cell death.

Life Cycle for Hair

Anagen period: Each hair cells have a shelf life that varies between 2 and 7 years, in this period, the hair grows is 1 cm every month. At the end of seven years, the cells renew him and the production of hair continues.The Anagen period, represents on average 90 percent of the human life. During this period, the problem of spillage or baldness does not occur.

Katagen period: During this period, the signs of a transition to the telogen phase appear. As hair growth ceases, the envelope in which there are hair cells are damaged and it crash. Referred to as pre-term of begin hair loss. It is likely to produce the hair loss or baldness, of the katagen period until the end of the telogen period.

During telogen period, the link between the hair and hair root weak and breaks. At this period, which lasts about 90 days, the hair separates from their roots and falls. At the end of the telogen period which can also be called the period of rest, the hair roots returns to the anagen period and starts the production of hair.

Each hair cell lives these three periods. These periods may be appointed as a cycle of life; it happen the birth, aging and death of a hair root. As a result, the loop begins again and continues to produce the hair. Indeed, these periods are not experienced at the same time for each hair roots. For this reason, you can sometimes have random drops or sometimes not have at all.