Polycystic ovary syndrome (PCOS), also called Stein-Leventhal Syndrome, is the most common endocrinologic disorder in women of reproductive age. Approximately 5-10% of reproductive age women have PCOS. This syndrome can have many symptoms. However, the two key components defining this disorder must include chronic anovulation (inability to ovulate an egg) and clinical hyperandrogenism (elevated male type hormones).

The various symptoms of PCOS can be irregular or absent menstrual cycles, infrequent or absent ovulation, excess facial and body hair, male pattern balding, acne of face/back/chest, and infertility. Other findings can include an elevated FSH to LH hormone ratio, elevated levels of male hormones, multiple small cysts of the ovaries and elevated cholesterol.

Some women with PCOS also suffer from other subtle endocrine abnormalities. One is insulin resistance, which affects sugar and fat metabolism, and may increase the long-term risks of heart disease, diabetes and high cholesterol. Insulin resistance (IR), the precursor state to diabetes, is present in 35-40% of women with PCOS, even if they are not overweight. Insulin resistance is diagnosed by blood testing, either as fasting glucose to insulin ratio, or as a complete glucose tolerance test (GTT). Long term follow up of women with PCOS reveals that up to 40% develop impaired glucose processing or diabetes by age 40. The prevalence of diabetes in women with PCOS is seven times higher than for the non-PCOS population. Excessive insulin production is thought to promote excess male hormone production, though the actual mechanism explaining this observation is still unclear.

The causes of PCOS are unknown. We do know that the imbalance of the ovarian hormones exists, which prevents the eggs from growing and ovulating every month. Additionally, this imbalance contributes to an excess of male hormone production by the ovaries, which can be worsened by insulin resistance. There is no cure for PCOS, though the various symptoms can be addressed and managed, and therefore help reduce the risk of long-term health consequences.