Hair Loss Information

What Causes Hair Loss?

Alopecia is the medical term for hair loss.

Alopecia is the general medical term for hair loss, and it has many different causes. Normal human hair can be classified according to their phases of growth. Anagen is the growing stage of hair, while telogen is the sleeping stage of hair. About 80 percent of the hairs in the human scalp are growing hair about 20 percent of them are sleeping hair. It has been estimated that the scalp normally contains about 100,000 hairs. Therefore, the average number of hairs that can be lost in a day is about 100. Contrary to popular belief, neither shaving nor hormonal changes, such as menstruation, has any effect upon hair growth.

Hair loss can be broken down into several different types, including “alopecia areata” (temporary hair loss in a coin-shaped patch), telogen effluvium (temporary hair loss secondary to a stressor on the system), and androgenetic alopecia (male-pattern hair loss). For the purposes of our discussion, we will focus on male-pattern hair loss. It generally shows itself in the 20s or early 30s by gradual loss of hair, chiefly on the top of the head and in the angles at the frontal hairline. There are several different patterns to this hair loss, but male-pattern hair loss is the most frequently encountered type. The exact mechanisms are still unknown. We have no doubt, however, that inherited factors and the effects of androgens (male hormones) on the hair are most responsible.

Is stress a factor in hair loss?
Stress does not cause hair loss—it simply makes a bad situation worse. Telogen effluvium, for example, occurs after an insult to the system. The most common cause is pregnancy. This can result in extensive and worrisome hair loss in women in the first few months after the birth of a baby. It is temporary and returns completely.

What is the relationship between genetics and hair loss?
Although not the primary cause of male-pattern hair loss, genetics does have a significant role in male-pattern hair loss. It is, however, polygenic, in that there is more than one factor at work. It is unclear whether having an affected mother or an affected father predisposes descendants to greater risk.

What can be the cause of a sudden loss of a large mass of hair?
Stressors to your system, such as illness, high fever, pregnancy, extreme weight loss or gain, and drug use, can cause temporary hair loss. This occurs when the ratio of growing to resting hairs is upset and more of the growing hair shifts into a resting phase. A greater quantity of normally sleeping hairs falls out, prompting a visit to the dermatologist. This type of hair loss is temporary and full re-growth should be expected.


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