What is a Simple Ovarian Cyst?

A simple ovarian cyst is a fluid-filled sac which can form on the ovary toward the middle or end of the menstrual cycle. Also known as a functional cyst, a simple ovarian cyst occurs due to a slight malfunction of the normal monthly processes by which an egg is shed. While this type of cyst can cause intense discomfort, it is usually harmless, and in fact affects a large number of women during their reproductive years. Often, a simple ovarian cyst will gradually disappear on its own, although extremely painful, recurrent, or stubborn cysts may require treatment with birth control pills or surgery.

Toward the beginning of a normal menstrual cycle, the ovary which is active that month develops a small sac, known as a follicle, containing the egg to be released. Upon receipt of a hormonal signal from the brain, the follicle releases the egg into the fallopian tube. The ruptured follicle then begins to prepare for the potential fertilization of the released egg by manufacturing large amounts of hormones.

Sometimes, however, this process does not occur exactly as it should. The follicle may fail to receive the hormonal signal instructing it to release its egg. Alternatively, following the egg’s release, the follicle may close up, preventing the discharge of the hormones it produces. In either case, the follicle begins to grow and swell. This growth is known as a simple ovarian cyst.

In some cases, a simple ovarian cyst can cause intense pelvic, bladder, and bowel discomfort, nausea, and irregular periods. This is especially likely if it grows to a large size or suddenly bursts. Quite often, however, this type of cyst causes no symptoms at all. In fact, many women become aware that they have a cyst only through a chance gynecological check-up.

Usually, a simple ovarian cyst is harmless. Even if a physician suspects this type of cyst, however, she may want to perform some tests to rule out a cancerous growth or other serious illness of the reproductive system. Diagnosis of cyst type may involve an ultrasound, a blood test, or examination of the ovary with a miniature camera called a laparoscope.

It is not uncommon for a simple ovarian cyst to gradually shrink and disappear on its own. Women with extremely painful or recurrent cysts, however, may benefit from medical treatment. Often, taking birth control pills can discourage the formation of new cysts. A cyst that does not disappear after two to three months may require surgical removal.