Enlarged ovaries (high ovarian volumes) are most commonly caused by ovarian cysts, but if the ovaries are enlarged without large cysts it can be a sign of Polycystic Ovarian Syndrome or PCOS, a hormonal condition that affects about 1 in 10 women. An ultrasound scan of your ovaries will look for ovarian cysts, and is part of the diagnostic tests that we do to look for PCOS, as well as blood testing.