The ovary is one of a pair of reproductive glands in women that are located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of a walnut. The ovaries produce eggs (ova) and female hormones estrogen and progesterone. The ovaries are the main source of female hormones, which control the development of female body characteristics such as the breasts, body shape, and body hair. They also regulate the menstrual cycle and pregnancy. Ovarian cysts are closed, sac-like structures within an ovary that contain a liquid, or semisolid substance. "Cyst" is merely a general term for a fluid-filled structure, which may or may not represent a tumor or neoplasm (new growth). If it is a tumor, it may be benign or malignant. The ovary is also referred to as the female gonad.
Ovarian cysts form for numerous reasons. The most common type is a follicular cyst, which results from the growth of a follicle. A follicle is the normal fluid-filled sac that contains an egg. Follicular cysts form when the follicle grows larger than normal during the menstrual cycle and does not open to release the egg. Usually, follicular cysts resolve spontaneously over the course of days to months. Cysts can contain blood (hemorrhagic cysts) from leakage of blood into the egg sac. Another type of ovarian cyst that relates to the menstrual cycle is a corpus luteum cyst. The corpus luteum is an area of tissue within the ovary that occurs after an egg has been released from a follicle. If a pregnancy doesn't occur, the corpus luteum usually breaks down and disappears. It may, however, fill with fluid or blood and persist as a cyst on the ovary. Usually, this cyst is found on only one side, produces no symptoms and resolves spontaneously.
Most ovarian cysts are small and don’t cause any problems. When there are symptoms, you might have pressure, bloating, swelling, or pain in the lower abdomen on the side of the cyst. This pain may be sharp or dull, and it can come and go.
Sometimes a cyst may need emergency attention. See your doctor right away if you have these symptoms:
• Sudden, severe belly pain
• Pain with fever and throwing up
• Dizziness, weakness, feeling faint
• Fast breathing
These signs could mean your cyst has caused the ovary to twist.