What is hair loss?

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.

Hair loss can be caused by:

• 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.

Other common causes of hair loss include:

• Ringworm of the scalp (tinea capitis), which is common in children.

• Mental stress or physical stress, such as recent surgery, illness, or high fever.

• Chemotherapy, the use of medication to destroy cancer cells.

• Pulling your hair back too tightly, wearing tight braids or ponytails, or using curling irons or dyes.

• Age. As you age, you grow less hair. It is also thinner and tends to break more easily.

Hair may be lost in two ways:

• In patchy hair loss, well-defined areas of hair are lost while the remaining scalp retains a good covering of hair.

• In generalized hair loss, there is a uniform thinning over the entire scalp with no areas of normal hair growth.

Is hair loss normal?

Everyone has some hair loss every day. In fact, it is normal to lose up to 100 hairs a day. However, some people lose a lot of hair early in life because it runs in their family (inherited) or because of disease, medications, stress, injury, or damage to the hair.

Will my hair grow back?

Whether your hair grows back depends on the cause of your hair loss. If you have inherited hair loss, you would need treatment to regrow your hair. It will not grow back naturally. However, treatment to regrow hair does not work for everyone. If your hair loss is caused by medication, stress, or damage, hair often grows back after the cause is removed, although sometimes treatment may be needed.

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