Polycystic ovary syndrome (PCOS) is a common hormonal and metabolic condition in women of reproductive age. It is diagnosed using the Rotterdam criteria — any two of three features: irregular or absent ovulation, signs of high androgens (such as acne or excess hair), and many small follicles on the ovaries seen on ultrasound — after other causes are ruled out.
The "cysts" are not painful cysts but immature follicles. Many women with PCOS also have insulin resistance. There is no cure, but symptoms and long-term risks are manageable — see PCOS symptoms and PCOS treatment.