What is PCOS? PCOS, or Polycystic Ovary Syndrome, is a condition in which a woman’s ovaries produce higher-than-normal levels of androgens (male hormones). This hormonal imbalance can interfere with ovulation and cause multiple small fluid-filled sacs (cysts) to form on the ovaries. PCOS affects 1 in 10 women during their reproductive years and is a leading cause of infertility.