About Polycystic Ovary Syndrome (PCOS)

PCOS is a set of symptoms related to a hormonal imbalance. These symptoms can include changes in metabolism, menstrual and reproductive health, and heart and blood function, as well as inflammatory responses and other outward characteristics.

What is PCOS?

PCOS is a set of symptoms related to a hormonal imbalance. People with PCOS usually have at least two of the following three features:¹

• Absence of ovulation (when the ovary releases a mature egg into the fallopian tube, usually monthly), leading to irregular menstrual periods or no periods at all
• High levels of hormones called androgens, or signs of high androgens, such as increased body or facial hair
• Growths in one or both ovaries, often clumps of ovarian follicles that have stopped developing²

Some people diagnosed with PCOS have the first two features, as well as symptoms of PCOS, but do not have growths in their ovaries. More recent genetic research suggests there may be two or more subtypes of PCOS defined by a set of genes or changes in specific genes.³

PCOS is the most common cause of anovulatory infertility, meaning that the infertility results from the absence of ovulation. Many people don't find out that they have PCOS until they have trouble getting pregnant.

People with PCOS may experience a range of symptoms that may seem unrelated to ovaries. For example, increased hair growth, dark patches of skin, acne, insulin resistance, and irregular menstrual bleeding are all possible symptoms of PCOS.