Polycystic Ovary Syndrome (PCOS) - UChicago Medicine (2024)

Polycystic ovary syndrome (PCOS) is an endocrine (hormonal) disorder. Most often, symptoms first appear in adolescence, around the start of menstruation. However, some women do not develop symptoms until their early to mid-20's. Although PCOS presents early in life, it persists through and beyond the reproductive years.

PCOS is estimated to affect between 5 and 10 percent of women of reproductive age, thus making it the most common hormonal disorder among women in this age group. It affects women of all races and nationalities.

No two women have exactly the same symptoms. The following characteristics are very often associated with PCOS but not all are seen in every woman:

• Hirsutism (excessive hair growth on the face, chest, abdomen, etc.)
• Hair loss (androgenic alopecia, in a classic "male baldness" pattern)
• Acne
• Polycystic ovaries
• Obesity
• Infertility or reduced fertility

In addition, women with PCOS appear to be at increased risk of developing the following health problems during their lives:

• Insulin resistance
• Diabetes
• Lipid abnormalities
• Obstructive sleep apnea
• Cardiovascular disease
• Endometrial carcinoma (cancer)

Because there is such variability in the clinical presentation of PCOS, there is not universal agreement among health professionals on how to best define the syndrome. What is clear, however, is that women with the disorder do not ovulate in a predictable manner and that women with PCOS also produce excessive quantities of androgens (particularly testosterone).

Polycystic ovaries are not present in all women diagnosed with PCOS. Also, many women with regular menstrual periods and normal testosterone levels have cystic ovaries.

It is important to make the distinction between polycystic ovaries and polycystic ovary syndrome. Polycystic ovaries are often, but not always, seen in women with PCOS. But, approximately 20 percent of women without menstrual or hormonal abnormalities have polycystic ovaries. The syndrome is thus defined by the menstrual and hormonal abnormalities with or without polycystic ovaries.

PCOS is also sometimes called "functional ovarian hyperandrogenism" or "ovarian androgen excess." But, because the term "polycystic ovary syndrome" has been used for more than six decades and is well-entrenched in both common usage and medical literature, its use is likely to continue.

PCOS develops when the ovaries overproduce androgens (e.g., testosterone). Androgen overproduction often results from overproduction of LH (luteinizing hormone), which is produced by the pituitary gland.

Research also suggests that when insulin levels in the blood are high enough, the ovary can be stimulated to produce more testosterone. That is, the combination of having ovaries that are responsive to insulin and high insulin levels in the blood, can result in the overproduction of testosterone.

Obesity, which itself can cause insulin levels to rise, may intensify PCOS. Yet, not all women who are overweight develop PCOS. Thus, there appears to be something unique about PCOS both in the excessively high insulin production and the increased sensitivity of the ovaries to the insulin that is produced.

Initially, many of the symptoms of PCOS — acne, obesity, excessive hair growth, and irregular periods — are viewed as unpleasant but unrelated. Many women are not diagnosed until the symptoms become advanced or until they experience difficulty with fertility.

There is no single, quick test to identify PCOS. Accurate diagnosis depends on the experienced skills of the clinician, a detailed medical history and laboratory studies. Some clinicians may choose to use some of the following diagnostic tools:

• Ultrasound to assess whether ovaries are enlarged and cystic
• Blood tests to detect elevated levels of androgens
• Blood test to detect high levels of LH (luteinizing hormone) or an elevation in the ratio of LH to FSH (follicle stimulating hormone)
• Monitoring the ovary's response to a stimulatory dose of gonadotropin-releasing hormone agonist (e.g., leuprolide), which is a test developed at the University of Chicago and used worldwide
• Checking the ovary's response to a suppressive dose of medications, such as dexamethasone

Physicians will also try to rule out other possible causes of irregular menstruation and excessive hair growth, such as Cushing's syndrome, congenital adrenal hyperplasia or other disorders of the pituitary or adrenal glands.

Evidence is accumulating to suggest that there is a hereditary basis for PCOS and its associated metabolic abnormalities, such as diabetes.

At UChicago Medicine, we have found that 1 in 3 women with PCOS will have an abnormal glucose tolerance test and that 1 in 10 will have diabetes by age 40. Women with PCOS who have a family history of diabetes appear to be at highest risk for abnormalities in glucose tolerance.

Thus, we are actively engaged in trying to understand whether the tendency for PCOS and glucose intolerance has a familial, genetic basis. To date, more than 200 families of women with PCOS have participated in testing in our Clinical Research Center.

If you and your immediate family members (parents or siblings) would like to participate in our study of the role of genetics in PCOS, please contact us at 773-702-4295. Most of the study can be done through the mail, so you can still participate even if you don't live close to Chicago.