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Polycystic Ovary Syndrome (PCOS)


JoAnn V. Pinkerton

, MD, University of Virginia Health System

Reviewed/Revised Feb 2023
Topic Resources

Polycystic ovary syndrome is characterized by irregular or no menstrual periods and often obesity or symptoms caused by high levels of male hormones (androgens), such as excess body hair and acne.

  • Typically, women have irregular or no periods, and often, they are overweight or obese and develop acne and characteristics caused by male hormones such as excess body hair).

  • Doctors often base the diagnosis on symptoms, but blood tests to measure hormone levels and ultrasonography may also be done.

  • Exercise, weight loss and/or medications with estrogen plus a progestin may help reduce symptoms (including excess body hair) and restore hormone levels to normal.

  • If women wish to become pregnant, losing weight and taking clomiphene and/or metformin, may result in release of an egg (ovulation).

Polycystic ovary syndrome affects about 5 to 10% of women.

In the United States, it is the most common cause of infertility.

This syndrome gets its name from the many fluid-filled sacs (cysts) that often develop in the ovaries, causing them to enlarge.

Did You Know...

  • Polycystic ovary syndrome is the most common cause of infertility in the United States.

In many women with polycystic ovary syndrome, the body’s cells resist the effects of insulin (called insulin resistance or sometimes prediabetes). Insulin helps sugar (glucose) pass into cells so that they can use it for energy. When cells resist its effects, sugar accumulates in the blood, and the pancreas produces more insulin to try to lower sugar levels in the blood. If insulin resistance becomes moderate or severe, diabetes may develop.

Causes of Polycystic Ovary Syndrome

What causes polycystic ovary syndrome is not clear. Some evidence suggests that it is caused by malfunction of the enzyme controlling the production of male hormones. This malfunction causes the production of male hormones (androgens) to increase.

High levels of male hormones increase the risk of metabolic syndrome Metabolic Syndrome Metabolic syndrome is characterized by a large waist circumference (due to excess abdominal fat), high blood pressure, resistance to the effects of insulin (insulin resistance) or diabetes,... read more (with high blood pressure, high cholesterol levels, and resistance to the effects of insulin) and risk of obesity. If male hormone levels remain high, the risk of diabetes, heart and blood vessel disorders (including atherosclerosis Atherosclerosis Atherosclerosis is a condition in which patchy deposits of fatty material (atheromas or atherosclerotic plaques) develop in the walls of medium-sized and large arteries, leading to reduced or... read more Atherosclerosis and coronary artery disease Overview of Coronary Artery Disease (CAD) Coronary artery disease is a condition in which the blood supply to the heart muscle is partially or completely blocked. The heart muscle needs a constant supply of oxygen-rich blood. The coronary... read more Overview of Coronary Artery Disease (CAD) ), and high blood pressure is increased. Also, some of the male hormones may be converted to estrogen, increasing estrogen levels. If not enough progesterone is produced to balance the increased level of estrogen and this situation continues a long time, the lining of the uterus (endometrium) may become extremely thick (a condition called endometrial hyperplasia) or cancer of the lining of the uterus Cancer of the Uterus The most common type of cancer of the uterus develops in the lining of the uterus (endometrium) and is called endometrial cancer. Endometrial cancer usually affects women after menopause. It... read more Cancer of the Uterus (endometrial cancer) may develop. Polycystic ovary syndrome may also increase the risk of nonalcoholic fatty liver disease Fatty Liver (abnormal accumulation of fats inside liver cells that is not related to alcohol consumption).

Symptoms of Polycystic Ovary Syndrome

Symptoms of polycystic ovary syndrome typically develop during puberty and worsen with time. Symptoms vary from woman to woman.

Sometimes in girls with polycystic ovary syndrome, menstrual periods do not start at puberty, and the ovaries do not release an egg (that is, women do not ovulate) or release an egg irregularly. Women or girls who have already started menstruation may have irregular vaginal bleeding or menstrual periods may stop.

Women may also develop symptoms related to the high levels of male hormones—called masculinization or virilization. Common symptoms include acne and an increase in body hair (hirsutism). Rarely, changes include a deepened voice, a decrease in breast size, an increase in muscle size, hair growth in a male pattern (for example, on the chest and face), and thinning of hair or baldness.

Many women with polycystic ovary syndrome have excess body weight, but some are thin. Producing too much insulin contributes to weight gain and makes losing weight difficult. Excess insulin due to insulin resistance may also cause skin in the armpits, on the nape of the neck, and in skinfolds to become dark and thick (a disorder called acanthosis nigricans).

Other symptoms may include fatigue, low energy, sleep-related problems (including sleep apnea), mood swings, depression, anxiety, and headaches.

Diagnosis of Polycystic Ovary Syndrome

  • A doctor's evaluation, based on specific diagnostic criteria

  • Ultrasonography

  • Measurement of hormone levels

Often, the diagnosis of polycystic ovary syndrome is based on symptoms.

Ultrasonography is done to see whether the ovaries contain many cysts and to check for a tumor in an ovary or adrenal gland. These tumors can produce excess male hormones and thus cause the same symptoms as polycystic ovary syndrome. Ultrasonography may be done to check for abnormalities in the ovaries. Transvaginal ultrasonography is done if possible. It involves using a small handheld device inserted through the vagina to view the interior of the uterus. Transvaginal ultrasonography is not usually used in adolescent girls because the changes of puberty make it less likely to help diagnose polycystic ovary syndrome.

Often, a biopsy of the uterine lining (endometrial biopsy) is done to make sure no cancer is present, particularly if women have abnormal vaginal bleeding.

In women with this syndrome, doctors may do other tests to check for complications or other conditions that often occur in women with polycystic ovarian syndrome. Doctors may measure blood pressure and usually levels of blood sugar and fats (lipids), such as cholesterol, to check for metabolic syndrome, which increases the risk of coronary artery disease.

Doctors may also do imaging tests to check for evidence of coronary artery disease. Imaging tests include coronary angiography (x-rays of arteries taken after a radiopaque contrast agent, which can be seen on x-rays, is injected into an artery) and computed tomography (CT) angiography (2- and 3-dimensional images of blood vessels taken after a radiopaque contrast agent is injected into a vein).

Treatment of Polycystic Ovary Syndrome

  • Exercise, dietary changes, and sometimes weight loss

  • Medications, such as birth control pills, metformin, or spironolactone

  • Management of excess body hair and acne

  • Management of long-term risks of hormone abnormalities

  • Infertility treatments if women want to become pregnant

The choice of treatment for polycystic ovary syndrome depends on the following:

  • Type and severity of symptoms

  • The woman’s age

  • Her plans regarding pregnancy

General measures

If insulin levels are high, lowering them may help. Exercising (at least 30 minutes a day) and reducing consumption of carbohydrates (in breads, pasta, potatoes, and sweets) can help lower insulin levels.

If women have excess body weight (overweight or obesity), weight loss may help with the following:

  • Lowering insulin levels enough that ovulation can begin

  • Increasing the chances of becoming pregnant

  • Making menstrual periods more regular

  • Reducing hair growth and the risk of thickening of the uterine lining


Women who do not wish to become pregnant are usually given a birth control pill that contains estrogen and a progestin (a combination oral contraceptive) or only a progestin (a synthetic form of the female hormone progesterone), such as that released by an intrauterine device Intrauterine Devices (IUDs) Intrauterine devices (IUDs) are small, flexible, T-shaped plastic devices that are inserted into the uterus. In the United States, 12% of women who use contraception use IUDs. IUDs are popular... read more Intrauterine Devices (IUDs) (IUD), or medroxyprogesterone. Either type of treatment may

  • Reduce the risk of endometrial cancer due to the high estrogen level

  • Make menstrual periods more regular

  • Help lower the levels of male hormones

  • Slightly reduce excess body hair and acne

Metformin, which is used to treat type 2 diabetes, may be used to increase sensitivity to insulin so the body does not have to make as much insulin. This drug may help women lose weight, and ovulation and menstrual periods may resume. If women take metformin and do not wish to become pregnant, they should use birth control. Metformin has little or no effect on excess hair growth, acne, or infertility. When metformin is used, women need to periodically have blood tests to measure glucose (sugar) and to evaluate kidney and liver function.

Medications that can help women with polycystic ovary syndrome lose weight include liraglutide (used to treat type 2 diabetes) and orlistat Medications Medications (used to treat obesity). Orlistat and inositols (which make insulin act more effectively) may reduce symptoms related to the high levels of male hormones (such as excess body hair) and lessen insulin resistance.

If women wish to become pregnant and have excess body weight, losing weight may help. Usually, these women are referred to an infertility specialist. Clomiphene (a fertility drug Treatment Women may have infertility if the ovaries do not release an egg each month, as usually occurs during a menstrual cycle. Ovulation may not occur at all or may occur irregularly if certain hormones... read more ) or letrozole is tried. These medications stimulate ovulation. If these medications are ineffective and the woman has insulin resistance, metformin may help because lowering insulin levels may trigger ovulation. If none of these medications is effective, other fertility treatments may be tried. They include follicle-stimulating hormone (to stimulate the ovaries), a gonadotropin-releasing hormone (GnRH) agonists Drugs used to treat endometriosis Drugs used to treat endometriosis (to stimulate the release of follicle-stimulating hormone), and human chorionic gonadotropin (to trigger ovulation).

If fertility medications are ineffective or if women do not wish to take them, surgery (such as ovarian drilling) may be tried. It is done by laparoscopy. Doctors make smalls incisions just above or below the navel. They then insert a thin viewing tube (called a laparoscope) into the abdominal cavity through one incision. Through another incision, they insert special tools that use an electric current or laser to destroy small areas of the ovaries that produce male hormones (androgens). Thus, androgen production is decreased. Decreasing the high levels of androgens in women with polycystic ovary syndrome can help regulate menstrual cycles and improve the chances of pregnancy. General anesthesia is required.

Treatment of excess body hair

Treatment of excess body hair Treatment In men, the amount of body hair varies greatly (see also Overview of Hair Growth), but very few men are concerned enough about excess hair to see a doctor. In women, the amount of hair that... read more Treatment includes bleaching or removal by electrolysis, plucking, waxing, hair-removing liquids or creams (depilatories), or laser. No treatments for removing excess hair is ideal or completely effective. The following may help:

  • Eflornithine cream may help remove unwanted facial hair.

  • Birth control pills may help, but they must be taken for several months before any effect, which is often slight, can be seen.

  • Spironolactone, a medication that blocks the production and action of male hormones, can reduce the amount of unwanted body hair. Side effects include increased urine production and low blood pressure (sometimes causing fainting). Spironolactone may not be safe for a developing fetus, so sexually active women taking the drug are advised to use effective birth control methods.

  • Cyproterone, a strong progestin that blocks the action of male hormones, reduces the amount of unwanted body hair in 50 to 75% of affected women. It is used in many countries but is not approved in the United States.

Gonadotropin-releasing hormone agonists and antagonists are being studied as treatment for unwanted body hair. Both types of medications inhibit the production of sex hormones by the ovaries. But both can cause bone loss and lead to osteoporosis.

Losing weight reduces production of androgens and thus may slow hair growth.

Treatment of acne

Drugs Mentioned In This Article

Generic Name Select Brand Names
Clomid, Serophene
Fortamet, Glucophage, Glucophage XR, Glumetza, Riomet, RIOMET ER
Aldactone, CAROSPIR
Amen, Depo-Provera, Depo-subQ Provera 104, Provera
Saxenda, Victoza
alli, Xenical
Iwilfin, Vaniqa
Acne Medication, Acne-10, Acneclear, Benprox , Benzac AC, Benzac W, Benzac-10, Benzac-5, Benzagel, Benzagel-10 , Benzagel-5, BenzaShave, BenzEFoam, BenzEFoam Ultra , BenzePrO, Benziq, Benziq LS, BP Cleanser, BP Cleansing Lotion, BP Foaming Wash, BP Gel, BP Topical , BP Wash, BP Wash Kit, BPO, BPO Creamy Wash, BPO Foaming Cloth, Brevoxyl-4, Brevoxyl-8, Clean&Clear Persa-Gel, Clearplex , Clearplex X, Clearskin, Clinac BPO, Del Aqua, Delos, Desquam-E, Desquam-X, EFFACLAR, Enzoclear, EPSOLAY, Ethexderm BPW, Inova Easy Pad, Lavoclen-4 , Lavoclen-8, NeoBenz Micro, NeoBenz Micro Cream Plus Pack, NeoBenz Micro SD, NeoBenz Micro Wash Plus Pack, Neutrogena Acne Cream, OC8, Oscion, Pacnex, Pacnex HP, Pacnex LP, Pacnex MX, PanOxyl, PanOxyl 10 Maximum Strength, PanOxyl 5, PanOxyl AQ, PanOxyl Aqua, PanOxyl-10, PanOxyl-5, PanOxyl-8, Peroderm, RE Benzoyl Peroxide , Riax, SE BPO, Seba, Seba-Gel, Soluclenz Rx , Theroxide, TL BPO MX, Triaz, True Marker Lintera, Zaclir, Zoderm Cleanser , Zoderm Cream, Zoderm Gel, Zoderm Redi-Pads , Zoderm Wash
Altinac, Altreno, Atralin, AVITA, Refissa, Renova, Retin-A, Retin-A Micro, Tretin-X, Vesanoid
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