What is the normal hair growth cycle?
Everyone is born with a fixed number of hair follicles on the scalp that produce hairs throughout life. Hair grows from the base of the follicle at a rate of about one centimetre a month for about three years. This growth phase is called anagen. After anagen, the hair dies (catagen hair) and no longer grows. It sits dormant in the follicle for a three-month phase called telogen. After telogen, the hair follicle undergoes another anagen phase to produce a new hair that grows out of the same follicle. As it grows, the old telogen hair is dislodged or pushed out. This is a cycle that continues throughout life.