Polycystic ovarian syndrome (PCOS) is the accumulation of underdeveloped follicles in the ovaries due to anovulation. It is is characterized by menstrual abnormalities and clinical or biochemical features of hyperandrogenism.
It results mainly from abnormal steroidogenesis that may be caused by insulin resistance leading to hyperinsulinemia.
There is increased sensitivity to androgens and the majority of women have elevated androgen levels.