Polycystic ovary syndrome, PCOS is a disorder affecting about 7% of women in the United States.

The classic symptoms of PCOS are irregular periods and unwanted hair growth or acne, but symptoms of PCOS can vary.  Women with PCOS have some combination of problems with ovulation, high testosterone or other male-like hormones, and/or ovaries that show many follicles on ultrasound.  The cause is currently unknown, but in some cases it may develop along with weight gain.

PCOS is a common cause of infertility, because women with infrequent ovulation do not release an egg from the ovary each month.  Without ovulation, there is no egg in the fallopian tube to be fertilized by sperm.  In order for women with PCOS to become pregnant, they may need a medication to cause ovulation.  Medications used for this purpose can include clomiphene citrate, letrozole, or injectable gonadotropins.  Women who have PCOS and are also overweight may sometimes be able to ovulate on their own, just by losing about 5% of their body weight.

If you think you may have PCOS, it is important to see a physician because you may also have an increased risk of high cholesterol, high blood pressure, diabetes or prediabetes, and heart disease, even if you are not overweight.  It is important to be screened for these health conditions.  All women should maintain a healthy lifestyle that includes regular exercise, but this is especially important for women with PCOS because of their risk for these health problems.  Also, PCOS is not the only health problem that can cause irregular periods, so it is important to check for these other conditions.  For example, thyroid problems or high prolactin can also lead to irregular periods.  Some inherited diseases can also cause unwanted hair growth or high testosterone.

Even if you are not trying to become pregnant, it is important to see a physician if you have irregular periods, because over time the lining of your uterus can become abnormal.  When the menstrual cycle is regular, there is a balance of the two important hormones, estrogen and progesterone.   When ovulation does not occur, the balance tips and estrogen becomes the dominant hormone.  This can be dangerous over time, and can even cause precancer or cancer to develop in the lining of your uterus.  Using hormones such as birth control pills to add progesterone back to your uterus can protect you from developing endometrial cancer.