Definition

The ovaries make eggs and female hormones. An ovarian cyst is a fluid-filled sac in the ovary. During the menstrual cycle, it is normal for the ovaries to make cysts. The largest of these normal cysts is usually less than an inch (2.5 cm). If you're taking birth control pills, then you usually do not form cysts larger than this size. Most cysts are small and benign. (Benign means that they are not cancerous). But, the larger ones can cause pain and other problems. When there is sudden and severe pain due to a cyst, it may because of:

  • Bleeding—blood irritates the surrounding tissue and causes pain
  • Torsion—the cyst twist around, disrupting blood flow to the ovary

One or many ovarian cysts can form.

Close Up of Ovary and Fallopian Tube

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© 2009 Nucleus Medical Art, Inc.

Causes

Follicles grow in the ovaries each month. They make hormones and release an egg during ovulation. In some cases, follicles may become cysts. There are two main types:

  • Functional cyst—occurs when a normal monthly follicle does not mature properly and the egg is not released
    • These cysts go away on their own within 1-3 menstrual cycles.
  • Follicular cyst—occurs after an egg is released
    • These cysts go away on their own in a few weeks.
    • These are a type of functional cyst.

Most are functional cysts. They only occur during childbearing years. Many other, less common types of benign cysts can also form from ovarian tissue. For example, if you have endometriosis , you may form cysts from the uterine tissue on an ovary.

Polycystic ovary syndrome is also linked to cysts. This happens when several small cysts (more than 10) grow in the ovaries.

In a small percentage of cases, cysts are caused by cancer .

Another condition linked to cysts is ectopic pregnancy . Your doctor will do a pregnancy test to rule this out.

Risk Factors

The main risk factor is being a woman of childbearing age.

Symptoms

Most ovarian cysts do not cause symptoms. The two most common symptoms are:

  • Pelvic pain
  • Menstrual bleeding

Pain is usually caused by:

  • Direct pressure from the cysts on the ovaries and surrounding structures
    • Causing chronic pelvic fullness or a dull ache
  • Bleeding from a cyst into and around the ovary
    • Causing more intense, sharp pain as the blood irritates the lining of the abdomen

Pain may come and go on a regular basis. Or, you may notice the pain more:

  • Just before or after your period
  • During sex

Other symptoms:

  • Urinary discomfort associated with bladder pressure or irritation
  • Nausea
  • Diarrhea

In rare cases, a cyst may become twisted. This can cut off its own blood supply, causing:

  • Severe abdominal pain
  • Vomiting
  • Fever

Call your doctor right away if you have these symptoms.

Diagnosis

The doctor will ask about your symptoms and medical history. She will also do a pelvic exam. Cysts are often found during routine pelvic exams when there are no symptoms.

If a cyst is suspected or found, the doctor may do a pelvic ultrasound . This is a test that uses sound waves to create images of the ovaries. Using this test, your doctor can determine:

  • Type and size of the cyst
  • Type of treatment needed

Other tests or procedures may be used if a cyst:

  • Does not go away after several menstrual cycles
  • Gets larger and more painful
  • Does not appear to be a simple functional cyst

Other tests may include:

  • Laparoscopy —a thin, lighted tube and other small instruments are inserted through several tiny incisions in the abdomen to look at the ovaries directly, drain fluid from a cyst, or take a sample for biopsy
  • Blood test for the protein CA-125 —done when a cyst is suspected of being cancerous
    • CA-125 is often elevated in the case of ovarian cancer. But it can also be elevated in benign situations.

Treatment

Treatment depends on:

  • Age
  • Menstrual status
  • Size and type of cyst
  • Symptoms

The main types of treatment are:

Wait and See

The doctor waits a few months to see if the cyst goes away on its own.

Medication

Birth Control Pills

If you have a functional cyst, your doctor may prescribe birth control pills . The pills may prevent other cysts from developing during the "wait and see" period. If you get cysts often, birth control pills decrease the chance of new ones forming.

Pain Medication

If your cyst is causing a lot of discomfort, your doctor may prescribe pain medication.

Laparoscopic Surgery

Pelvic laparoscopy may be recommended to remove a cyst if it:

  • Grows larger or reaches a size greater than two inches
  • Has some solid material in it, or other features
  • Causes persistent or worsening symptoms
  • Lasts longer than two or three menstrual cycles
  • Disrupts blood flow

If the cyst is not cancerous, often just the cyst can be removed. However, in some cases, your whole ovary may need to be removed. If the cyst is cancerous, you may have both ovaries and uterus removed. This requires an open surgical procedure .

If you are diagnosed with an ovarian cyst, follow your doctor's instructions .

Prevention

Ovarian cysts are common and are usually painless and benign. Doctors do not routinely recommend preventive interventions. Birth control pills may help you if the cysts keep coming back. Taking birth control pills for more than five years has also been shown to reduce the risk of ovarian cancer.

The best way to catch cysts early is to:

  • Tell your doctor about any changes in your monthly cycles or periods.
  • Report pelvic and abdominal pain.