The new hair may push the old hair out. Sometimes therefore you may see two hairs in the same follicle. The average daily loss of hair on the scalp is between sixty and one hundred hairs. If the loss is over one hundred hairs daily, hair loss will exceed replacement, and you eventually become bald. During the year you may notice a loss of extra hair in the autumn and spring, than in summer which is related to daylight and the weather.
Hair growth is fastest from the age of sixteen to the late twenties.
The average number of hairs on the scalp of an adult is 100,000. Blondes have more hairs with around 140,000 while redheads have the least with about 90,000. It is no fallacy that on occasions, such as when you are frightened, your hair literally stands on end. Attached to the hair shaft are tiny muscles called the arrectores pilorum, or erect pili muscles that, as the name suggests, cause the hairs to become erect. Under the influence of nervous excitation, these muscles contract and cause the hairs to which they are linked to become rigid.