- Resources for Patients
- The Endocrine System
- What is an Endocrinologist?
- What Do Hormones Do?
- Endocrine Diseases and Conditions
- Myth vs. Fact
- Downloadable Resources
- Cooking for Pleasure and Health
- Menopause Map
- Living Your Best Life with Diabetes
- Resources for Health Professionals
- En Español
- Endocrinology: Science & Policy
An estimated 5 to 7 million women in the United States alone suffer with the effects of Polycystic Ovary Syndrome. Also known as Polycystic Ovarian Syndrome, PCOS is the most common hormonal disorder among women of reproductive age and is a leading cause of infertility. Even worse, the disorder often goes undiagnosed because of its many baffling and seemingly unrelated symptoms. Read more about Polycystic Ovary Syndrome and advances in reproductive endocrinology and treatment for PCOS on The Hormone Health Network's web section and related fact sheets.
Polycystic Ovary Syndrome (PCOS) is a common problem in the United States, and is one of the most prevalent endocrine system diseases, affecting as many as 7 to 10 out of 100 (or 7 to 10 percent) of women of childbearing age (15 to 45 years). In all, an estimated 5 to 7 million women suffer with the effects of this condition in the United States alone. PCOS is the most common hormonal disorder among women of reproductive age and is a leading cause of infertility.
Definition of PCOS
While the ovaries and adrenal glands of all women release small amounts of 'male hormones,' called androgens, women with Polycystic Ovary Syndrome produce levels of these types of hormones in slightly higher amounts. Androgens play a role in helping women grow and develop strong bones and muscles strength, and in sexual function. However, higher levels of this hormone lead to hormone imbalance that can interfere with ovulation and normal egg development. Instead of maturing and being released as usual, each month, the cysts containing the eggs build up in the ovaries. This results in irregular or infrequent ovulation and, in most women, irregular and infrequent menstruation or vaginal bleeding.
The build-up of egg-containing cysts within the ovary then leads to the 'polycystic' appearance of the ovaries, and to their frequent enlargement in size, in Polycystic Ovary Syndrome. However, it is important to note that there is a distinction between the large cysts (generally bigger than 1 inch) sometimes seen in women and which may need more careful medical attention, and the small cysts seen in women with Polycystic Ovary Syndrome. We should also note that it is normal for all women who are of child-bearing age to have a few small cysts in their ovaries, since these hold the eggs that will ovulate in the next few cycles.
While Polycystic Ovary Syndrome was identified almost 80 years ago by Drs. Stein and Leventhal, and is sometimes called the Stein-Leventhal Syndrome, the cause remains unknown. Research suggests that many women with Polycystic Ovary Syndrome may have decreased sensitivity to insulin, called 'insulin resistance.' Insulin, a hormone produced by the pancreas, is necessary to carry sugar from the bloodstream into the cells, where it is converted into energy. When cells are resistant to insulin, it means that the effect of insulin on sugar, and other functions, is deficient. More insulin than normal is required to be produced by the pancreas to ensure that the body cells absorb enough sugar. This leads to high insulin levels in the blood stream which, among other effects, make the ovaries overproduce male hormones, leading to a hormone imbalance that triggers or worsens some of the symptoms of PCOS. The high insulin levels may also cause areas of the skin (for example on the neck) to darken or develop skin tags. Eventually, the pancreas may not be able to maintain the high insulin levels necessary to keep sugar levels normal and the patient develops diabetes.
Finally, Polycystic Ovary Syndrome seems to run in families, and it is likely that it is a genetic disorder. Sisters of polycystic ovary syndrome patients have about a 50% chance of also having PCOS.
While there is still no cure for Polycystic Ovary Syndrome, many effective treatment options are available. Together with changes in diet and exercise, these treatments are empowering women with PCOS to lead healthier and more satisfying lives. Even the problem of infertility can often be corrected and conception can occur.
Learn more about Polycystic Ovary Syndrome by reading the following fact sheets: