(See also Overview of Hair Growth.)
In men, the amount of body hair varies greatly, but very few men are concerned enough about excess hair to see a doctor. In women, the amount of hair that is considered excessive varies depending on ethnic background and culture. Usually, excess body hair is only a cosmetic and psychologic concern. However, the cause sometimes is a serious hormonal disorder, particularly in women who develop masculine characteristics.
Hairiness can be categorized as
Hirsutism is excessive growth of thick or dark body hair in women in locations that are more typical of male hair growth. Such locations include the face (on the upper lip, chin, or sideburn area), torso (around the nipples or on the chest, lower abdomen, or back), and limbs (on the shoulders or inner thighs).
Hirsutism usually results from high levels of male hormones (androgens, such as testosterone) or from increased sensitivity to normal levels of male hormones in the body. Testosterone stimulates hair growth in the pubic area and underarms. Dihydrotestosterone stimulates hair growth in the beard area and hair loss at the scalp.
Virilization is development of other masculine characteristics than hirsutism. For example,
Hypertrichosis is an increase in the amount of hair anywhere on the body in either sex. The excess hair may grow all over the body or only in specific locations. The hair may be fine, light-colored, and downlike or thick, dark, and long. This disorder may be present at birth or develop later.
Hair growth depends on the balance between male and female hormones. Male hormones stimulate the growth of thick, dark hair. Female hormones (such as estrogen) slow hair growth or make the hair finer and lighter-colored. Women normally produce small amounts of male hormones, and men produce small amounts of female hormones.
Conditions that tip the hormonal balance in favor of male hormones can cause hirsutism. The balance may be tipped by excess production of male hormones. However, in hirsutism that runs in families (familial hirsutism), women's hair follicles simply appear to be more sensitive to normal levels of male hormones.
The most common cause of hirsutism is
There are many less common causes of hirsutism (see Table: Some Causes and Features of Hirsutism):
Pituitary, ovarian, or adrenal gland disorders that result in overproduction of male hormones
Tumors that produce male hormones (including certain tumors of the ovaries, adrenal glands, lungs, or digestive tract)
Use of certain drugs, such as anabolic steroids, danazol, or birth control pills (oral contraceptives) that have a high dose of progesterone
A familial trait, most often occurring in people of Mediterranean, Middle Eastern, or South Asian descent
Most commonly, hypertrichosis is caused by
Certain complications of cancer (paraneoplastic syndromes)
Use of certain drugs, most commonly minoxidil, phenytoin, cyclosporine, or the prostaglandin eye drops bimatoprost or latanoprost
A serious systemic disorder, such as AIDS, brain disorders or injuries, undernutrition (including eating disorders such as anorexia nervosa and bulimia), dermatomyositis, and porphyria
Repeated injury to and/or friction or inflammation of areas of skin (for example, an increase in hair growth that is noticed after a cast has been removed from a previously broken arm or leg)
Rarely, hypertrichosis is caused by a gene mutation. In such cases, it is usually present at birth.
Doctors must determine whether the excess hair results from a disorder or is simply a cosmetic concern.
In women with excess body hair, certain symptoms are cause for concern:
The sudden appearance of excess hair may suggest cancer.
If warning signs are present, people should see a doctor promptly. If excess hair appears gradually without warning signs, people should see a doctor, but the visit does not need to be scheduled as quickly.
Typically, women without warning signs do not need to see a doctor if they have always had excess hair, they otherwise feel well, they have regular menstrual periods and no other masculine characteristics, and have family members who also have excess hair. Such women have excess body hair because it runs in their family.
Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause and the tests that may need to be done (see Table: Some Causes and Features of Hirsutism).
Women are asked when hair began to grow excessively and where it is located, whether they have menstrual periods, and, if so, whether periods are regular. Doctors also ask whether women have had problems conceiving a child and whether any family members also have excess hair.
Doctors ask people about all the drugs they are taking, particularly anabolic steroids and other drugs known to cause hair growth.
During the physical examination, doctors note the pattern of hair growth and look for other masculine characteristics and for other features that suggest a cause. For example, a lump felt during the pelvic examination suggests a tumor in an ovary.
Some Causes and Features of Hirsutism
Unless doctors confirm that the cause is use of a drug, blood tests are done to measure levels of various hormones and thus identify the cause.
If Cushing syndrome is suspected or an adrenal tumor is detected, urine tests are also done.
Ultrasonography or computed tomography (CT) of the pelvis or both are usually done to rule out cancer, particularly if a lump is found in the pelvis or if male hormone levels are high.
The underlying condition is treated or corrected. For example, drugs that may cause hirsutism are stopped or changed.
Treatment for the excess hair is unnecessary unless women wish to minimize or remove it for cosmetic reasons. If excess hair growth is not related to increased levels of male hormones, physical methods are used to remove the hair. If increased levels of male hormones are the cause, hormone therapy is needed in addition to physical methods.
Several methods are available.
Depilation removes the part of the hair above the surface of the skin. Methods include shaving and over-the-counter creams, which may contain barium sulfate and/or calcium thioglycolate.
Epilation involves removing intact hairs with their roots. Methods to temporarily remove hairs include tweezing, plucking, waxing, and epilating devices used at home. Some methods have longer-lasting, sometimes permanent effects, but the treatments often must be repeated. These methods include electrolysis, thermolysis, and laser treatments.
Usually, hormones used to treat hirsutism must be taken for a long time because most of the disorders that cause high male hormone levels cannot be cured. These hormones include birth control pills and drugs that block the effects of male hormones, such as finasteride, flutamide, or spironolactone. Women who are pregnant or who could become pregnant should not take a drug that blocks male hormones because it can cause feminine characteristics to develop in a male fetus.
Metformin, a drug used to treat diabetes, can reduce levels of testosterone but is less effective than other drugs. Gonadotropin-releasing hormone agonists (such as leuprolide) can be used if the ovaries are producing extremely high levels of male hormones, but use of these drugs requires close supervision by a gynecologist or an endocrinologist. Corticosteroids can be used to reduce levels of male hormones produced by adrenal gland tumors.
Bleaching is an alternative to hair removal. It is inexpensive and works well when women have only a small amount of excess hair. Bleaches lighten the color of the hair, making it less noticeable. Several types of hair-bleaching products are available. Most products contain hydrogen peroxide.
Eflornithine cream, applied twice a day, slows the rate of hair growth and, with long-term use, may increase the amount of time between hair removal treatments.
Excess body hair may run in families, and what is considered excessive may vary with ethnic background and culture.
Hirsutism, which occurs only in women, causes excess body hair to grow in a male pattern and differs from hypertrichosis, which occurs in men and women and causes excess hair to grow anywhere on the body.
Polycystic ovary syndrome (PCOS) is the most common cause of hirsutism.
If women also develop male characteristics (such as a deepened voice, increased muscle mass, scalp hair loss, or irregular or absent menstrual periods), they may have a disorder that requires prompt evaluation by a doctor.
If excess body hair appears suddenly and grows rapidly, the cause may be cancer.
Treatment may include hair removal and/or hormonal therapy.