Where and how much hair develops is dependent on her genetic make-up and ethnic background. Women of Mediterranean descent tend to develop more terminal hair on the arms and legs than do women of Asian ancestry, while women of European descent fall somewhere in the middle when it comes to developing body hair.
Our modern society has deemed that body hair on women is an undesired trait, and over the years women have developed a habit of shaving the body parts where such unwanted hairs are found (underarms, legs, etc.). Even the parts of the body where such hair is expected are carefully "groomed" so as not to appear "too hairy". This attitude toward body hair on women has become so ingrained (at least in American culture) that the sight of a woman with normal hair development is considered grotesque.
Yet, millions of women today experience what can be categorized as abnormal hair growth. Such hair growth is heavier than would be normal for someone of a particular ethnic background and genetic parentage. There are many factors which can cause this type of hair growth. The best method of dealing with the growth depends on which of the factors (or combination of factors) is the cause of the growth in a specific case. The most common factors for abnormal hair growth are:
• Altered Androgen Metabolism - The skin and fat cells of the body can convert
weak forms of androgens (male hormones) into more potent ones. Altered
Androgen Metabolism causes abnormal hair growth when the skin and fat cells
convert testosterone into dihydrotestosterone (DHT).
• Increased Androgen Production - The ovaries produce testosterone as a part of
normal developmental function. Likewise, the adrenal glands naturally produce
dehydroepiandrosterone sulfate. When either of these glands over-produces
their respective androgens abnormal hair growth can result. The cause is more
often the fault of the ovaries than the adrenal glands, but there are several
recognized instances where the adrenal gland causes such problems.
• Decreased Androgen Binding in the Circulation - The hormone levels in the
body are regulated and balanced normally. The liver produces a substance
called Sex Hormone Binding Globulin (SHBG) which binds testosterone into an
inactive form. Estrogen stimulates the liver to produce SHBG which in turn
reduces the amount of free androgens in the blood. Androgens decrease SHBG
in the blood. A decrease in estrogen will also decrease SHBG production,
therefore increasing the amount of free androgens available in the blood, and
only free androgens are biologically viable. With more free androgens there is
an increase in hair growth.
• Exogenous Androgens - Sometimes a person taking medications for hormone
therapy (Estratest, danazol), body development (such as anabolic steroids and
body-building supplements) or to control pregnancy (birth control pills
containing norgestrel) can develop abnormal hair growth. Even certain
hormone-containing skin creams (used to treat specific conditions) can be
absorbed into the bloodstream and result in hair growth.
The first thing a woman should do who is concerned about an abnormal amount of hair growth (or about growth in unusual areas) is to consult her doctor. With a few blood tests he can usually pinpoint the specific cause of the abnormal hair growth and advise her on the best course of treatment for the underlying cause.