PCOS is the most common hormonal reproductive problem in women of childbearing age.
What are ovaries?
The ovaries are a pair of organs in the female reproductive system. They are located in the pelvis, one on each side of the uterus, which is the hollow, pear-shaped organ where a baby grows. Each ovary is about the size and shape of an almond. The ovaries produce eggs and female hormones. Hormones are chemicals that control the way certain cells or organs function.
Every month, during the menstrual cycle, an egg is released from one ovary in a process called ovulation. The egg travels from the ovary through the fallopian tube to the uterus. The ovaries are also the main source of the female hormones estrogen and progesterone. These hormones influence the development of a woman's breasts, body shape, and body hair. They also regulate the menstrual cycle and pregnancy.
What are ovarian cysts?
A cyst is a fluid-filled sac, and can be located anywhere in the body. On the ovary, different types of cysts can form. The most common type of ovarian cyst is called a functional cyst, which often forms during the normal menstrual cycle. Each month, a woman's ovaries grow tiny cysts that hold the eggs. When an egg is mature, the sac breaks open to release the egg, so it can travel through the fallopian tube for fertilization. Then the sac dissolves. In one type of functional cyst, called a follicular cyst, the sac doesn't break open to release the egg and may continue to grow. This type of cyst usually disappears within one to three months. A corpus luteum cyst, another type of functional cyst, forms if the sac doesn’t dissolve. Instead, the sac seals off after the egg is released. Fluid then builds up inside of it. This type of cyst usually goes away on its own after a few weeks. However, it can grow to almost four inches and may bleed or twist the ovary and cause pain. Clomid or Serophene, which are drugs used to induce ovulation, can raise the risk of getting this type of cyst. These cysts are almost never associated with cancer.
There are also other types of cysts:
- Endometriomas. These cysts develop in women who have endometriosis, when tissue from the lining of the uterus grows outside of the uterus. The tissue may attach to the ovary and form a growth. These cysts can be painful during sexual intercourse and during menstruation.
- Cystadenomas. These cysts develop from cells on the outer surface of the ovary. They are often filled with a watery fluid or thick, sticky gel. They can become large and cause pain.
- Dermoid cysts. The cells in the ovary are able to make hair, teeth, and other growing tissues that become part of a forming ovarian cyst. These cysts can become large and cause pain.
- Polycystic ovaries. The eggs mature within the follicles, or sacs, but the sac doesn't break open to release the egg. The cycle repeats, follicles continue to grow inside the ovary, and cysts form. For more information about polycystic ovaries, refer to our FAQ on Polycystic Ovarian Syndrome.