Polycystic Ovary Syndrome

By Marcie Richardson, MD |

Polycystic ovary syndrome (PCOS, also called anovulatory androgen excess, polycystic ovarian disease, or Stein-Leventhal syndrome) is the most common hormonal and reproductive problem that affects women of childbearing age. It is a medical condition that may include a variety of ailments, making it difficult to diagnose.

PCOS usually starts around the time of puberty but may become noticeable when a woman is in her twenties or thirties. Between approximately five and eight percent of women experience this disorder­.

PCOS is defined by the presence of any two of the following characteristics:

  • Irregular menstrual cycles or lack of ovulation (release of an egg) for an extended period of time
  • Elevated levels of androgens (male hormones) in the blood, or evidence for elevated androgens such as acne or excess unwanted hair growth (and head hair loss)
  • Many small follicles (benign fluid-filled sacs) on the ovaries (resulting from not releasing eggs)

PCOS is diagnosed in large part by excluding other possible conditions that can cause similar signs and symptoms. Your healthcare provider will first administer blood tests or other exams to see if your body is making high doses of steroids, or if there are pituitary, adrenal, or ovarian tumors.

What Causes PCOS?

The exact cause of PCOS is unclear, although risk increases in women who are overweight. PCOS is more common in certain families. There is evidence for a genetic cause, but the exact gene(s) responsible have yet to be identified.

PCOS results from a combination of several related factors. Many women with PCOS have insulin resistance, in which the body cannot use insulin efficiently. This leads to high blood levels of insulin, called hyperinsulinemia. It is believed that hyperinsulinemia is related to increased androgen levels, as well as to obesity and type 2 diabetes. In turn, obesity can also cause insulin resistance and increase the risk for or worsen PCOS.

Large amounts of androgens can block egg growth and ovulation. Because they are male sex hormones, they can also cause women to develop male secondary sex characteristics such as facial hair or hair thinning at the front of the head.

How Does PCOS Affect Ovulation?

When a woman has an ovulatory problem, her reproductive system does not produce the necessary amounts of hormones to develop, mature, and release a healthy egg. In this case, the ovaries become enlarged and develop many small follicles. These follicles produce androgens, which further interfere with ovulation.

Some researchers believe that the cysts contain eggs that didn’t mature and didn’t get released during ovulation. Others disagree. Studies have shown that not every woman with PCOS has these numerous follicles. Nor does every woman with these numerous follicles have PCOS. Some women with polycystic ovaries have regular menstrual cycles.

PCOS Symptoms

The signs and symptoms of PCOS are related to hormonal imbalance (excess male hormones), lack of ovulation, and insulin resistance and may include:

  • Irregular, infrequent, or absent menstrual periods
  • Hirsutism—excessive growth of body and facial hair including hair on the chest, stomach, and back
  • Acne or oily skin
  • Enlarged and/or polycystic ovaries
  • Problems with fertility
  • Being overweight or obese, especially around the waist (central obesity)
  • Male-pattern baldness or thinning hair
  • Skin tags—small pieces of skin on the neck or armpits
  • Acanthosis nigricans—darkened skin areas on the back of the neck, in the armpits, and under the breasts

In addition, women with PCOS may be at increased risk for developing certain health problems, including:

  • Type 2 diabetes
  • Elevated cholesterol levels. Triglycerides— fatty acids in the bloodstream—may be higher than normal in some women with PCOS, whereas HDL, the “good cholesterol,” may be lower than normal. This could raise the risk of heart attacks because arteries and other blood vessels are more likely to be narrowed or clogged over time.
  • High blood pressure
  • Elevated blood clotting factors
  • Missed periods followed by prolonged and heavy bleeding
  • Endometrial cancer. Lack of ovulation for an extended period of time may cause excessive thickening of the endometrium (the lining of the uterus). Abnormal cells may build up in the lining of the uterus when it is not shed regularly during a menstrual period. Eventually, some of these abnormal cells may turn cancerous.
  • Some studies show a relationship between PCOS and breast cancer.

The symptoms of PCOS may resemble other conditions or medical problems. Always consult your physician for a diagnosis.


In addition to a complete medical history, a physical examination, including a pelvic exam, can be used initially to diagnose PCOS.

A variety of tests can also be used to detect PCOS. Blood tests are used to detect increased levels of androgens and other hormones. Other blood tests can measure blood sugar, cholesterol, and triglyceride levels.

Physicians sometimes use an ultrasound (also called a sonogram)—a diagnostic technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function and to assess blood flow through various vessels. Ultrasound can determine if a woman’s ovaries are enlarged and if cysts or follicles are present, and also evaluate the thickness of the endometrium.

Sometimes it can be difficult to diagnose PCOS with certainty because of how it varies, both from woman to woman and even over time in the same woman.

Medical and Self-Help Treatments for PCOS

Specific treatment for PCOS will be determined by your clinician based on your age, overall health, and medical history. In addition, your healthcare provider will take into account the extent of the disorder and expectations for improvement; your tolerance for specific medications, procedures, and therapies; and your preferences. Treatment also depends on whether or not you want to become pregnant.

For women who do not want to become pregnant, treatment is focused on treating the symptoms and preventing long-term consequences of the condition. Treatment may include the following.

Healthy habits: A healthy diet and increased physical activity allow more efficient use of insulin and decrease blood glucose levels, and also lower risk of heart disease and diabetes. Some women with PCOS who lose weight will start having regular periods.

Oral contraceptives: Birth control pills may be prescribed to regulate menstrual cycles, decrease androgen levels, control acne, prevent balding or hair thinning, and decrease facial hair.

Cyclic progesterone: Can be prescribed intermittently to ensure women don’t go too long without a period.

Spironolactone: A less common but often helpful treatment that can minimize excess hair growth. Other procedures such as bleaching, electrolysis, and laser hair removal may also be used to decrease facial hair.

Diabetes medication: Metformin, a medication used in the treatment of type 2 diabetes, is often used to decrease insulin resistance in PCOS. Some preliminary studies of women with PCOS who are insulin resistant show that such drugs may also help reduce androgen levels, hair growth, acne, balding, and body weight and may help a woman ovulate more regularly. No long-term studies of this form of treatment are available. Some studies have shown a reduction in the risk of miscarriage in pregnant PCOS patients taking metformin, while others have not. Your clinicians will discuss this with you if you become pregnant.

For women who want to become pregnant, treatment is focused on weight reduction and promoting ovulation and may include the following.

Weight reduction: A healthy diet and increased physical activity allow more efficient use of insulin and decrease blood glucose levels and may help a woman ovulate more regularly.

Ovulation induction medications such as Clomid: These medications stimulate the ovary to make one or more follicles (sacs that contain eggs) and release the egg for fertilization. Metformin is sometimes used for this purpose as well.

Surgery: In cases of infertility where drugs don’t work, surgical techniques that make small holes in one or both ovaries may be suggested. This surgery often restores ovulation, though not always permanently. Adhesions—scar tissue that can twist the ovaries or make them cling to other organs—are a potential drawback. Because of these concerns, this procedure is rarely performed today.

Based upon a patient information handout from Harvard Vanguard Medical Associates in Boston, MA.