Ovaries are a woman’s reproductive organs that make female hormones and release an egg from a follicle (a small fluid-filled sac) each month. The follicle is usually about 2–3 cm when measured across (diameter) but sometimes can be larger.
An ovarian cyst is a larger fluid-filled sac (more than 3 cm in diameter) that develops on or in an ovary. A cyst can vary in size from a few centimetres to the size of a large melon. Ovarian cysts may be thin-walled and only contain fluid (known as a simple cyst) or they may be more complex, containing thick fluid, blood or solid areas.
This information is for you if you are premenopausal (have not gone through the menopause) and your doctor thinks you might have a cyst on one or both of your ovaries. It tells you about cysts on the ovary and the tests and treatment you may be offered.
This information aims to help you and your healthcare team make the best decisions about your care. It is not meant to replace advice from a doctor about your situation.