Each hair has a growth cycle which lasts about 3 to 6 years and then it again restarts.
1 ANAGEN PHASE It is GROWTH PHASE of the hair in which continuous growth in the length takes place.Each hair grows from its root which is embedded in the skin and take its blood supply from the dermal papilla.At any given time about 85 to 90 percent of hair in the scalp are in Anagen Phase.This growth phase lasts for 3 to 6 years and after that the hair root gets Tired.
2 CATAGEN PHASE It is also called TRANSITION PHASE of the hair in which it gets disconnected from its blood supply. The hair stops growing and gradual thinning starts.This stage lasts 2 to 4 weeks.
3 TELOGEN PHASE It is also called RESTING PHASE of the hair .Usually 5 to 10 percent of scalp hair are in this stage at any given time.The hair progressively gets thinner and finally gets detached and falls off.Normally one loses 50 to 100 hair per day.
4 CYCLE RESTARTS After the hair falls, new hair follicle develops at the base of the dermal papilla and new hair starts to sprout from the same root. So in an average life span a person loses and regrows hair from the same root about 20 to 30 times