The growth cycle of hair 

An average, hair grows 1.25 cm (½ inch) per month. It is also estimated that on an average we lose 80-100 hair a day. A single strand does not grow continuously throughout its life. 

The stages of the life cycle of hair are: 

1.anagen 

2. catagen 

3. telogen 

4. Exogen

1. Anagen 

During the anagen phase, the hair follicle is active and the hair is growing continuously. New hair in early anagen grows faster than old hair, the average growth being 1.25 cm per month.

2.Catagen 

The next phase of the hair growth cycle is called as ‘catagen’. During this cycle, hair follicle undergoes a period of change and do not grow. This phase lasts for about 2 weeks. New cells are formed. At any time only about 1% of follicles are in the catagen stage.

3. Telogen 

This is the period of rest for hair follicles. This stage lasts for about 3-4 months. Approximately 13% of the follicles are in the telogen state at any one time.

4.Exogen 

After the resting period, follicles begin to lengthen. When the follicle reaches full length, a new hair begins to grow.