Reviewed by Joseph Maloney, M.D.
Many women experience ovarian cysts during their pre-menopausal years. Women who have had ovarian cysts in the past are at a higher risk of developing them again.
The cause of ovarian cysts is unknown.
Each month during ovulation, an egg ripens in one of the follicles in a woman’s ovary and is released. In order for the egg to be released, the follicle ruptures. When this happens the follicle develops into a smaller sac, called the corpus luteum. If the egg remains unfertilized, the corpus luteum is reabsorbed and a new follicle begins to grow for the next menstrual cycle. If the egg is fertilized, the corpus luteum remains for the first few months of pregnancy, secreting vital hormones for the developing embryo.
Two main types of functional ovarian cysts exist: follicular cysts and corpus luteum cysts. Follicular cysts either develop when the follicle ruptures to release the egg, or when the follicle fails to release the egg and just continues to enlarge. They tend to be painless, and usually disappear within 60 days. They are rarely larger than one to two inches in diameter.
Whereas follicular cysts are often undetected, corpus luteum cysts are usually painful. Corpus luteum cysts can develop after ovulation, and are filled with fluid or blood. They can grow from the size of a golf ball to the size of a grapefruit. Corpus luteum cysts usually cause pain on one side of the abdomen, and may not reabsorb as quickly as follicle cysts.
Often times, the pain associated with corpus luteum cysts is sharp, which may mean one of two things: either the cyst has ruptured, or it is undergoing a process called torsion, in which the stem of the cyst becomes twisted.
In some cases, a condition called polycystic ovarian syndrome (also known as Stein-Leventhal Syndrome) causes multiple cysts to form on the ovary. This condition is caused by hormone irregularities in the body and can cause scarring and infertility.