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
• Hypertrichosis

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 inner thigh). 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. Sometimes other masculine characteristics develop—a condition called virilization. For example, the voice deepens, muscle size increases, hair is lost from the head, the clitoris (the smaller female organ that corresponds to the penis) becomes larger, and menstruation becomes irregular or stops completely. Acne may also develop.

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. Hypertrichosis that develops later can usually be treated.

Causes

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.

Hirsutism: 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

• Polycystic ovary syndrome (most common—see Menstrual Disorders and Abnormal Vaginal Bleeding: Polycystic Ovary Syndrome)

There are many uncommon causes of hirsutism (see Hair Disorders: 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

Hypertrichosis: Most commonly, hypertrichosis is caused by

• Certain complications of cancer (paraneoplastic syndromes—see Symptoms and Diagnosis of Cancer: What Are Paraneoplastic Syndromes?)
• A drug, most commonly minoxidil, phenytoin, or cyclosporine
• A serious bodywide disorder, such as AIDS, brain disorders or injuries, undernutrition (as occurs in carbohydrate deficiencies and eating disorders including anorexia nervosa), 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.

Evaluation

Doctors must determine whether the excess hair results from a disorder or is simply a cosmetic concern.

Warning signs: In women with excess body hair, certain symptoms are cause for concern:

• Development of masculine characteristics (virilization), such as a deepened voice, increased muscle size, baldness, decreased or absent menstrual periods, and acne
• Sudden appearance and rapid growth of excess hair (over weeks to months)

The sudden appearance of excess hair may suggest cancer.

When to see a doctor: If warning signs are present, people should see a doctor promptly, within a week or so. If excess hair appears gradually without warning signs, people should see a doctor, but the visit need not 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.

What the doctor does: 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 Hair Disorders: 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.

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Some Causes and Features of Hirsutism Cause Common Features* Tests Adrenal gland disorders Development of masculine characteristics (virilization) caused by adrenal hyperplasia (enlarged adrenal glands that produce abnormally large amounts of male hormones) The presence of masculine characteristics, such as a deepened voice, baldness, an enlarged clitoris, increased muscle size, irregular or absent menstrual periods, and acne When adrenal hyperplasia is present at birth, external genital organs that are not clearly male or female (ambiguous) Blood and sometimes urine tests to measure hormone levels A dexamethasone suppression test (dexamethasone, taken by mouth, followed several hours later by a blood test to measure hormone levels) Adrenal tumors (usually cancerous) Development of masculine characteristics or Cushing syndrome, which can occur suddenly In girls who have not gone through puberty, an unusually fast increase in height or an early end of growth, resulting in a short adult height MRI or CT Cushing syndrome Excess fat throughout the torso, a pad of fat between the shoulders (buffalo hump), thin arms and legs, purple streaks on the abdomen, and a large, round face (moon face) Urine tests to measure the level of cortisol (which may be high in Cushing syndrome) Sometimes a dexamethasone suppression test Sometimes blood tests to measure the level of cortisol No disorder present Familial hirsutism Hirsutism in family members No other symptoms (normal menstrual cycles and no other masculine characteristics) A doctor's examination Blood tests to measure hormone levels (which are normal) Ovarian disorders Polycystic ovary syndrome Hirsutism that begins after puberty Development of masculine characteristics, obesity, infertility, menstrual irregularities, acne, decreased sensitivity to insulin, and darkened and thickened skin in the underarms, on the nape of the neck, and in skinfolds (acanthosis nigricans) A doctor's examination Blood tests to measure levels of hormones, such as testosterone, luteinizing hormone, and follicle-stimulating hormone Usually ultrasonography Tumors Sometimes one or more of the following symptoms, which often begin suddenly: Pelvic pain Abdominal swelling or bloating Weight loss Development of other masculine characteristics Ultrasonography Sometimes CT or MRI Pituitary disorders A pituitary adenoma (a noncancerous tumor) that secretes prolactin Production of breast milk in women who are not breastfeeding (galactorrhea) No menstrual periods Sometimes vision problems Blood tests to measure the level of prolactin MRI of the brain A pituitary disorder that causes Cushing disease (such as a pituitary tumor) See Cushing syndrome, above Blood and sometimes urine tests to measure the level of cortisol (which may be high in Cushing disease) A dexamethasone suppression test MRI of the brain Drugs Androgenic drugs: Anabolic steroids, including those taken to enhance athletic performance, such as testosterone products and danazol Birth control pills that have a high dose of progesterone Development of male characteristics Use of anabolic steroids (sometimes not admitted by the user) A doctor's examination *Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present. CT = computed tomography; MRI = magnetic resonance imaging. Some Causes and Features of Hirsutism Cause Common Features* Tests Adrenal gland disorders Development of masculine characteristics (virilization) caused by adrenal hyperplasia (enlarged adrenal glands that produce abnormally large amounts of male hormones) The presence of masculine characteristics, such as a deepened voice, baldness, an enlarged clitoris, increased muscle size, irregular or absent menstrual periods, and acne When adrenal hyperplasia is present at birth, external genital organs that are not clearly male or female (ambiguous) Blood and sometimes urine tests to measure hormone levels A dexamethasone suppression test (dexamethasone, taken by mouth, followed several hours later by a blood test to measure hormone levels) Adrenal tumors (usually cancerous) Development of masculine characteristics or Cushing syndrome, which can occur suddenly In girls who have not gone through puberty, an unusually fast increase in height or an early end of growth, resulting in a short adult height MRI or CT Cushing syndrome Excess fat throughout the torso, a pad of fat between the shoulders (buffalo hump), thin arms and legs, purple streaks on the abdomen, and a large, round face (moon face) Urine tests to measure the level of cortisol (which may be high in Cushing syndrome) Sometimes a dexamethasone suppression test Sometimes blood tests to measure the level of cortisol No disorder present Familial hirsutism Hirsutism in family members No other symptoms (normal menstrual cycles and no other masculine characteristics) A doctor's examination Blood tests to measure hormone levels (which are normal) Ovarian disorders Polycystic ovary syndrome Hirsutism that begins after puberty Development of masculine characteristics, obesity, infertility, menstrual irregularities, acne, decreased sensitivity to insulin, and darkened and thickened skin in the underarms, on the nape of the neck, and in skinfolds (acanthosis nigricans) A doctor's examination Blood tests to measure levels of hormones, such as testosterone, luteinizing hormone, and follicle-stimulating hormone Usually ultrasonography Tumors Sometimes one or more of the following symptoms, which often begin suddenly: Pelvic pain Abdominal swelling or bloating Weight loss Development of other masculine characteristics Ultrasonography Sometimes CT or MRI Pituitary disorders A pituitary adenoma (a noncancerous tumor) that secretes prolactin Production of breast milk in women who are not breastfeeding (galactorrhea) No menstrual periods Sometimes vision problems Blood tests to measure the level of prolactin MRI of the brain A pituitary disorder that causes Cushing disease (such as a pituitary tumor) See Cushing syndrome, above Blood and sometimes urine tests to measure the level of cortisol (which may be high in Cushing disease) A dexamethasone suppression test MRI of the brain Drugs Androgenic drugs: Anabolic steroids, including those taken to enhance athletic performance, such as testosterone products and danazol Birth control pills that have a high dose of progesterone Development of male characteristics Use of anabolic steroids (sometimes not admitted by the user) A doctor's examination *Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present. CT = computed tomography; MRI = magnetic resonance imaging.

Testing: 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.

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.

If Cushing syndrome is suspected or an adrenal tumor is detected, urine tests are also done.

Treatment

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.

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 (OTC) 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 (see Noncancerous Skin Growths: Using Lasers to Treat Skin Problems).

Hormonal therapy: Usually, hormones used to treat hirsutism must be taken 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 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 it 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.

Other methods: 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 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.

Key Points

• 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 hair to grow in a male pattern and differs from hypertrichosis, which is excess hair anywhere on the body and can occur in men or women.
• Polycystic ovary syndrome 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.

Last full review/revision September 2012 by Wendy S. Levinbook, MD