Most people routinely lose between 70 and 150 hairs from their scalp each day, mainly through washing, brushing, and combing.
Scalp hair starts to thin when more hairs are lost through normal shedding than the scalp is able to renew. About 40% of the density of scalp hair has to be lost before thinning of the hair becomes noticeable.
CAUSES OF HAIR LOSS
Heredity. Most balding is caused by a genetic predisposition – in other words, it’s part of a person’s genetic makeup. This is called male pattern baldness, or hereditary balding or thinning. It is the most common cause of thinning hair.
Illness, certain physical conditions, or their treatments. This can include high fever, thyroid disease, childbirth, inadequate protein in the diet, iron deficiency, cancer treatments, the use of certain medications, and other causes
Your doctor will ask you some questions, like how much hair you’re losing, when it started, and whether your parents have hair loss. He or she will look closely at your scalp and hair loss pattern and may gently pull out a few hairs for tests.