Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Hair fall in some people causes psychological distress. Everybody loses some hair every day. Research has shown that a person can lose up to 100 hairs per day. But losing more hair can cause bald spots to appear on a man’s head. In the case of a woman, there is thinning of the hair on the top of her head.