Ovarian cysts are small, fluid-filled sacs that usually are not malignant. They may not cause any symptoms, or they may be quite painful. Sometimes, ovarian cysts appear in connection with the menstrual cycle, and they may go away on their own in a few months. When these cysts grow large, they may cause feelings of pressure or fullness.

Ovarian cysts are fluid filled cavities within the ovary. Each month fluid collects around the developing egg forming a follicle. After ovulation the follicle becomes a corpus luteum which makes progesterone. Either a follicle or a corpus luteum can form a cyst (follicular or corpus luteum cysts). There are also benign (non cancerous) and rarely (cancerous) cysts which can form in the ovary.

During ovulation (the process during which the egg ripens and is released from the ovary) the ovary produces a hormone to make the follicles (sacs containing immature eggs and fluid) grow and the eggs within it mature.

Ovarian cysts are fluid-filled sacs that develop on the ovaries, the female reproductive organs that produce eggs. Women can develop ovarian cysts as a normal part of their menstrual cycle as the ovaries prepare eggs to release into the fallopian tubes. While many of these cysts are completely benign (not harmful to health), some ovarian cysts can be malignant, meaning they pose a danger to health.

An ovarian cyst is a fluid-filled sac that develops near the surface of the ovary. The ovaries are two small organs on each side of a woman's uterus that produce eggs and female hormones. Mostly an ovarian cyst is small and benign (not cancerous). However, the larger ovarian cyst can cause pain and other problems. A woman can develop one or many ovarian cysts.

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.

Functional, or physiological, ovarian cysts usually disappear within 8 - 12 weeks without treatment. They are relatively common, and are more common during a woman's childbearing years (puberty to menopause). Ovarian cysts are rare after menopause.

Many women experience no symptoms when they have an ovarian cyst, particularly if it's small. Certain cysts grow large and may cause the abdomen to swell. Depending on where the cyst is and its size, it may put pressure on the bladder or bowels, making you need to go to the toilet more often. You may also notice abdominal discomfort and sex may be uncomfortable or painful. Your periods may be affected; they may become irregular or the bleeding may be heavier or lighter than usual.

Cysts are fluid-filled sacs. The cysts in the ovaries can be identified with imaging technology. (However, as noted above, women without PCOS can have many cysts as well.) Ultrasound, which passes sound waves through the body to create a picture of the kidneys, is used most often. Ultrasound imaging employs no injected dyes or radiation and is safe for all patients including pregnant women.