ovarian cyst

What is ovarian cyst

A cyst is a fluid-filled sac. It can form in many places in the body. Women have two ovaries — each about the size and shape of an almond — on each side of the uterus. Eggs (ova), which develop and mature in the ovaries, are released in monthly cycles during the childbearing years. Ovarian cysts are fluid-filled sacs or pockets in an ovary or on its surface 1. Many women have ovarian cysts at some time and usually form during ovulation. Ovulation happens when the ovary releases an egg each month. Many women with ovarian cysts don’t have symptoms. Most ovarian cysts present little or no discomfort and are harmless 2. The majority disappears without treatment within a few months.

Ovarian cysts are common in women with regular periods. In fact, most women make at least one follicle or corpus luteum cyst every month. You may not be aware that you have a cyst unless there is a problem that causes the cyst to grow or if multiple cysts form. Ovarian cysts — especially those that have ruptured — can cause serious symptoms 1. To protect your health, get regular pelvic exams and know the symptoms that can signal a potentially serious problem 1.

About 8% of premenopausal women develop large cysts that need treatment 3.

Ovarian cysts are less common after menopause. Postmenopausal women with ovarian cysts are at higher risk for ovarian cancer.

At any age, see your doctor if you think you have a cyst. See your doctor also if you have symptoms such as bloating, needing to urinate more often, pelvic pressure or pain, or abnormal (unusual) vaginal bleeding. These can be signs of a cyst or other serious problem.

Are ovarian cysts ever an emergency ?

Yes, sometimes 2. If your doctor told you that you have an ovarian cyst and you have any of the following symptoms, get medical help right away:

  • Pain with fever and vomiting
  • Sudden, severe abdominal pain
  • Faintness, dizziness, or weakness
  • Rapid breathing

These symptoms could mean that your cyst has broken open, or ruptured. Sometimes, large, ruptured cysts can cause heavy bleeding 2.

Can you prevent ovarian cysts ?

No, you cannot prevent functional ovarian cysts if you are ovulating 2. If you get ovarian cysts often, your doctor may prescribe hormonal birth control to stop you from ovulating. This will help lower your risk of getting new cysts.

Figure 1. Female reproductive system

normal ovary

Figure 2. Normal ovary

normal ovary

Figure 3. Ovarian cyst

ovarian cyst

Types of ovarian cysts

The most common types of ovarian cysts are called functional cysts, they form during the menstrual cycle (see Figure 2. Normal ovary) 2. They are usually benign (not cancerous) 2. Functional cysts are usually harmless, rarely cause pain, and often disappear on their own within two or three menstrual cycles.

The two most common types of functional cysts are 2:

  • Follicle cysts. In a normal menstrual cycle, an ovary releases an egg each month. The egg grows inside a tiny sac called a follicle. When the egg matures, the follicle breaks open to release the egg. Around the midpoint of your menstrual cycle, an egg bursts out of its follicle and travels down the fallopian tube. Follicle cysts form when the follicle doesn’t break open to release the egg. This causes the follicle to continue growing into a cyst. Follicle cysts often have no symptoms and go away in one to three months.
  • Corpus luteum cysts. Once the follicle breaks open and releases the egg, the empty follicle sac shrinks into a mass of cells called corpus luteum. Corpus luteum makes hormones estrogen and progesterone to prepare for the next egg for the next menstrual cycle. Corpus luteum cysts form if the sac doesn’t shrink. Instead, the sac reseals itself after the egg is released, and then fluid builds up inside. Most corpus luteum cysts go away after a few weeks. But, they can grow to almost four inches wide. They also may bleed or twist the ovary and cause pain. Some medicines used to cause ovulation can raise the risk of getting these cysts.

Other types of benign ovarian cysts are less common:

  • Endometriomas are caused by endometriosis. Endometriosis happens when the lining of the uterus (womb) grows outside of the uterus. Some of the lining of the uterus tissue can attach to your ovary and form a growth.
  • Dermoids (also called teratomas) come from cells present from birth and do not usually cause symptoms. Dermoid cysts these can contain tissue, such as hair, skin or teeth, because they form from embryonic cells. They’re rarely cancerous 4.
  • Cystadenomas develop on the surface of an ovary and might be filled with a watery or a mucous material. They can sometimes grow large.

Dermoid cysts and cystadenomas can become large, causing the ovary to move out of position. This increases the chance of painful twisting of your ovary, called ovarian torsion. Ovarian torsion may also result in decreasing or stopping blood flow to the ovary.

In some women, the ovaries make many small cysts. This is called polycystic ovary syndrome (PCOS). PCOS can cause problems with the ovaries and with getting pregnant.

Malignant (cancerous) cysts are rare 2. They are more common in older women. Cancerous cysts are ovarian cancer. For this reason, ovarian cysts should be checked by your doctor. Most ovarian cysts are not cancerous.

Causes of ovarian cyst


The most common causes of ovarian cysts include 2:

  • Hormonal problems. Functional cysts usually go away on their own without treatment. They may be caused by hormonal problems or by drugs used to help you ovulate.
  • Endometriosis. Women with endometriosis can develop a type of ovarian cyst called an endometrioma. The endometriosis tissue may attach to the ovary and form a growth. These cysts can be painful during sex and during your period.
  • Pregnancy. An ovarian cyst normally develops in early pregnancy to help support the pregnancy until the placenta forms. Sometimes, the cyst stays on the ovary until later in the pregnancy and may need to be removed.
  • Severe pelvic infections. Infections can spread to the ovaries and fallopian tubes and cause cysts to form.
  • A previous ovarian cyst. If you’ve had one, you’re likely to develop more.

Complications of ovarian cyst

Some women develop less common types of cysts that a doctor finds during a pelvic exam. Cystic ovarian masses that develop after menopause might be cancerous (malignant). That’s why it’s important to have regular pelvic exams.

Infrequent complications associated with ovarian cysts include:

  • Ovarian torsion. Cysts that enlarge can cause the ovary to move, increasing the chance of painful twisting of your ovary (ovarian torsion). Symptoms can include an abrupt onset of severe pelvic pain, nausea and vomiting. Ovarian torsion can also decrease or stop blood flow to the ovaries.
  • Rupture. A cyst that ruptures can cause severe pain and internal bleeding. The larger the cyst, the greater the risk of rupture. Vigorous activity that affects the pelvis, such as vaginal intercourse, also increases the risk.

Symptoms of ovarian cyst

Most ovarian cysts are small and don’t cause symptoms.

If a cyst does cause symptoms, you may have pressure, bloating, swelling, or pain in the lower abdomen on the side of the cyst 2. This pain may be sharp or dull and may come and go 2.

If a cyst ruptures, it can cause sudden, severe pain 2.

If a cyst causes twisting of an ovary, you may have pain along with nausea and vomiting 2.

Less common symptoms include:

  • Pelvic pain
  • Dull ache in the lower back and thighs
  • Problems emptying the bladder or bowel completely
  • Pain during sex
  • Unexplained weight gain
  • Pain during your period
  • Unusual (not normal) vaginal bleeding
  • Breast tenderness
  • Needing to urinate more often

Diagnosis of ovarian cyst

If you have symptoms of ovarian cysts, talk to your doctor. Your doctor may do a pelvic exam to feel for swelling of a cyst on your ovary.

A cyst on your ovary can also be found during a routine pelvic exam. Depending on its size and whether it’s fluid filled, solid or mixed, your doctor likely will recommend tests to determine its type and whether you need treatment.

Tests include:

  • Pelvic ultrasound. This test uses sound waves to create images of the body. With ultrasound, your doctor can see the cyst’s: Shape / Size / Location / Mass (whether it is fluid-filled, solid, or mixed)
  • Pregnancy test to rule out pregnancy. A positive test might suggest that you have a corpus luteum cyst.
  • Hormone level tests to see if there are hormone-related problems
  • Blood test. If you are past menopause, your doctor may give you a test to measure the amount of cancer-antigen 125 (CA-125) in your blood. The amount of CA-125 is higher with ovarian cancer.  If your cyst is partially solid and you’re at high risk of ovarian cancer, your doctor might order this test. In premenopausal women, many other illnesses or diseases besides cancer can cause higher levels of CA-125. Elevated CA 125 levels can also occur in noncancerous conditions, such as endometriosis, uterine fibroids and pelvic inflammatory disease.
  • Laparoscopy. Using a laparoscope — a slim, lighted instrument inserted into your abdomen through a small incision — your doctor can see your ovaries and remove the ovarian cyst. This is a surgical procedure that requires anesthesia.


Treatment of ovarian cyst

Treatment depends on your age, the type and size of your cyst, and your symptoms. Your doctor might suggest 5:

  • Watchful waiting. In many cases you can wait and be re-examined to see if the cyst goes away within a few months. This is typically an option — regardless of your age — if you have no symptoms and an ultrasound shows you have a simple, small, fluid-filled cyst.

Your doctor will likely recommend that you get follow-up pelvic ultrasounds at intervals to see if your cyst changes in size.

  • Medication. Your doctor might recommend hormonal contraceptives, such as birth control pills, to keep ovarian cysts from recurring. However, birth control pills won’t shrink an existing cyst.
  • Surgery. Your doctor might suggest removing a cyst that is large, doesn’t look like a functional cyst, is growing, continues through two or three menstrual cycles, or causes pain. The National Institutes of Health estimates that 5% to 10% of women have surgery to remove an ovarian cyst. Only 13% to 21% of these cysts are cancerous 6.

Your cyst may require surgery if you are past menopause or if your cyst:

  • Does not go away after several menstrual cycles
  • Gets larger
  • Looks unusual on the ultrasound
  • Causes pain

If your cyst does not require surgery, your doctor may:

  • Talk to you about pain medicine. Your doctor may recommend over-the-counter medicine or prescribe stronger medicine for pain relief.
  • Prescribe hormonal birth control if you have cysts often. Hormonal birth control, such as the pill, vaginal ring, shot, or patch, help prevent ovulation. This may lower your chances of getting more cysts.

If your cyst requires surgery, your doctor will either remove just the cyst or the entire ovary.

Surgery can be done in two different ways:

  • Laparoscopy. With this surgery, the doctor makes a very small cut above or below your belly button to look inside your pelvic area and remove the cyst. This is often recommended for smaller cysts that look benign (not cancerous) on the ultrasound.
  • Laparotomy. Your doctor may choose this method if the cyst is large and may be cancerous. This surgery uses a larger cut in the abdomen to remove the cyst. The cyst is then tested for cancer. If it is likely to be cancerous, it is best to see a gynecologic oncologist, who may need to remove the ovary and other tissues, like the uterus.

Some cysts can be removed without removing the ovary (ovarian cystectomy). In some cases, your doctor might suggest removing the affected ovary and leaving the other intact (oophorectomy).

If a cystic mass is cancerous, your doctor will likely refer you to a gynecologic cancer specialist. You might need to have your uterus, ovaries and fallopian tubes removed (total hysterectomy) and possibly chemotherapy or radiation. Your doctor is also likely to recommend surgery when an ovarian cyst develops after menopause.

Can ovarian cysts lead to cancer ?

Yes, some ovarian cysts can become cancerous 2. But most ovarian cysts are not cancerous 2.

The risk for ovarian cancer increases as you get older. Women who are past menopause with ovarian cysts have a higher risk for ovarian cancer. Talk to your doctor about your risk for ovarian cancer. Screening for ovarian cancer is not recommended for most women 7. This is because testing can lead to “false positives.”  A false positive is a test result that says a woman has ovarian cancer when she does not.

Can ovarian cysts make it harder to get pregnant ?

Typically, no 2. Most ovarian cysts do not affect your chances of getting pregnant 2. Sometimes, though, the illness causing the cyst can make it harder to get pregnant.

Two conditions that cause ovarian cysts and affect fertility are 2:

  • Endometriosis, which happens when the lining of the uterus (womb) grows outside of the uterus. Cysts caused by endometriosis are called endometriomas.
  • Polycystic ovary syndrome (PCOS), one of the leading causes of infertility (problems getting pregnant). Women with PCOS often have many small cysts on their ovaries.

How do ovarian cysts affect pregnancy ?

Ovarian cysts are common during pregnancy 2. Typically, these cysts are benign (not cancerous) and harmless 8. Ovarian cysts that continue to grow during pregnancy can rupture or twist or cause problems during childbirth. Your doctor will monitor any ovarian cyst found during pregnancy.

  1. Mayo Foundation for Medical Education and Research. Ovarian cysts. http://www.mayoclinic.org/diseases-conditions/ovarian-cysts/home/ovc-20341904[][][]
  2. The Office on Women’s Health, U.S. Department of Health and Human Services. Ovarian cysts. https://www.womenshealth.gov/a-z-topics/ovarian-cysts[][][][][][][][][][][][][][][][][][][]
  3. Ross, E.K. (2013). Incidental Ovarian Cysts: When to Reassure, When to Reassess, When to Refer. Cleveland Clinic Journal of Medicine; 80(8): 503–514. https://www.ncbi.nlm.nih.gov/pubmed/23908107[]
  4. Mayo Foundation for Medical Education and Research. Symptoms and causes of Ovarian cysts. http://www.mayoclinic.org/diseases-conditions/ovarian-cysts/symptoms-causes/dxc-20341906[]
  5. Mayo Foundation for Medical Education and Research. Treatment of Ovarian cysts. http://www.mayoclinic.org/diseases-conditions/ovarian-cysts/diagnosis-treatment/treatment/txc-20341929[]
  6. NIH consensus conference (1995). Ovarian cancer: screening, treatment, and follow-up. NIH Consensus Development Panel on Ovarian Cancer. JAMA; 273: 491–497. https://www.ncbi.nlm.nih.gov/pubmed/7837369[]
  7. U.S. Preventive Services Task Force (2016). Screening for Ovarian Cancer. https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/ovarian-cancer-screening[]
  8. Horowitz, N.S. (2011). Management of adnexal masses in pregnancy. Clinical Obstetrics & Gynecology; 54: 519–527. https://www.ncbi.nlm.nih.gov/pubmed/22031242[]
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