What is the ovary and what are ovarian cysts?
Ovarian cysts are fluid-filled sacs or pockets within or on the surface of an ovary. Women have two ovaries - each about the size and shape of an almond - located on each side of the uterus. Eggs (ova) develop and mature in the ovaries and are released in monthly cycles during your childbearing years.
Many women have ovarian cysts at some time during their lives. Most ovarian cysts present little or no discomfort and are harmless. The majority of ovarian cysts disappear without treatment within a few months.
However, ovarian cysts - especially those that have ruptured - sometimes produce serious symptoms. The best ways to protect your health are to know the symptoms that may signal a more significant problem, and to schedule regular pelvic examinations.
What causes ovarian cysts?
Most ovarian cysts start during the normal function of your menstrual cycle. These are known as functional cysts. Other types of cysts are much less common.
Your ovaries normally grow cyst-like structures called follicles each month. Follicles produce the hormones estrogen and progesterone and release an egg when you ovulate. Sometimes a normal monthly follicle just keeps growing. When that happens, it becomes known as a functional cyst. There are two types of functional cysts:
The fertility drug clomiphene (Clomid, Serophene), which is used to induce ovulation, increases the risk of a corpus luteum cyst developing after ovulation. These cysts don't prevent or threaten a resulting pregnancy.
Functional cysts are usually harmless, rarely cause pain, and often disappear on their own within two or three menstrual cycles.
Some types of cysts are not related to the normal function of your menstrual cycle. These cysts include:
Dermoid cysts and cystadenomas can become large, causing the ovary to move out of its usual position in the pelvis. This increases the chance of painful twisting of your ovary, called ovarian torsion.
Pressure on your rectum or bladder that causes a need to urinate more frequently or difficulty emptying your bladder completely.