What is normal and natural hair replacement?

Normal person can have more than 100,000 strands of hair on his scalp. New strands of hair grow out of the hair follicles. Normal hair fall is approximately 100-125 hairs per day.
Hair grows for a period of 2-6 years before becoming dormant and gradually falls off and in its place new hairs are replaced. This dormant period is called as "resting phase"