Hair loss

Natural shedding

As we saw in Chapter 1, all hairs naturally fall out at the end of the growing period. Everyone loses between 50 and 80 hairs a day. They tend to come out with brushing and shampooing. So if you wash your hair only once a week, it is perfectly in order for you to lose several hundred hairs at one go!
    Sometimes, however, a person may start to lose more hairs than usual. If this hair loss is significant, and if it persists, then sooner or later the scalp may become visible through the thinning hair. The condition is called alopecia. The name comes from the Greek word alopekia, which means 'fox': foxes (and also dogs) sometimes suffer from bald patches due to an unpleasant disease called mange. (Fortunately, humans do not get mange!)

Baldness

The commonest kind of hair loss is simple baldness. Many people find this type of baldness embarrassing and distressing, but it is not a disease - it is a perfectly normal event. For thousands of years, however, it has caused concern and anxiety, and people have sought remedies and 'cures' without number, in spite of some of them being uncomfortable and even painful.
    Baldness affects both men and women. It is much more obvious in men, however. By the age of 25, 25% of men have lost some of their hair, and the proportion rises to 50% by the age of 50. Many men accept, however reluctantly and vainly hoping that it may not be so, that they are likely to go partly or completely bald if their fathers have done so. They are right, in that baldness is genetically determined in both men and women. In women, however, baldness is not only unexpected, particularly in the twenties and thirties let alone later, but understandably unacceptable.
    In men, baldness usually begins at the temples, above the forehead and at the crown of the head. In these areas the hair follicles of sufferers are genetically pre-programmed to revert from producing terminal hairs to producing vellus-like hairs. The growth phase of

the hair (anagen) becomes shorter and shorter, with a greater proportion of hairs in the shedding (telogen) phase.
    This change happens under the influence of male hormones (androgens) and can begin as early as the time of puberty or soon after, when androgen production in the body reaches a peak. Scientists call this kind of baldness androgenetic alopecia (meaning 'baldness due to androgens'). The eunuchs who served the harems of the east in days gone by never went bald!
    Most women who come to dermatologists with hair thinning have androgenetic alopecia too. Baldness in women usually starts ten years or so later than in men, however. Fortunately for the sufferers, the amount of loss in women is differently distributed and less dramatic. The hairline usually remains intact and there is little or no loss at the temples.
    The patterns of baldness thus differ between men and women. Hair scientists speak of male pattern baldness and female pattern baldness. Occasionally, though rarely, women suffer from male pattern baldness and men from female pattern baldness.