Ovarian Cysts

Any ovarian follicle (a small, hollow, sphere-shaped group of cells in the ovary), that contains a single ovum or egg and that is larger than 0.8 inches (2 cm) is considered an ovarian cyst. Ovarian cysts can be as small as a pea or as large as an orange or cantaloupe.

Tanya's Story

Tanya is an eighth-grader who had her first menstrual * period shortly after her 12th birthday. Her periods were irregular for the first several months, which she knew is normal for girls in early puberty * . After her periods became more regular, however, Tanya noticed a sharp cramping pain on one side of her abdomen between periods. At first she did not think much about the cramps because they went away after a few hours. The cramps got worse with each month, however, and one month they were so bad that Tanyás parents thought she might have appendicitis. They took their daughter to the emergency room because she was in great pain.

Ovarian Cysts

Illustration by Argosy, Inc. © 2016 Cengage Learning®.

The doctors in the emergency room checked Tanya right away because they knew that appendicitis is not unusual in teenagers and must be treated as soon as possible. They gave her an ultrasound * test to get a clearer picture of the organs in her abdomen. The doctors found that Tanya did not have appendicitis; instead, she had some simple ovarian cysts that looked like bubbles on the ultrasound image of her ovaries. The doctors explained to Tanya and her parents that this type of cyst occurs when the follicle in the ovary that releases an egg each month ruptures. It was the bursting of the follicle that caused the sharp cramps that Tanya felt halfway between her periods. This type of pain is called mittelschmerz *

Tanya was relieved to find out that her cramps did not indicate a serious health problem and that she could treat them at home with an over-the-counter pain reliever. She was surprised, however, to learn that teenagers and even young girls can develop ovarian cysts.

What Is an Ovarian Cyst?

An ovarian cyst is any collection of fluid larger than 0.8 inches (2 cm) that develops inside a thin wall of tissue in the ovary. Ovarian cysts can occur in young girls and older women after menopause * , although they are most common in women of childbearing age. Most ovarian cysts are harmless, do not produce any noticeable symptoms, and are related to the normal functions of a woman's body during the menstrual cycle. Some cysts, however, are malignant * and need to be removed by surgery, whereas others may need to be removed because they are causing pain or bleeding even though they are benign * .

Functional ovarian cysts

The majority of ovarian cysts are functional, which means that they result from the normal functioning of a woman's ovaries. This type of cyst is also called a simple cyst. To better understand how functional cysts develop, it is useful to review the process of ovulation * .

Women have two ovaries, one on each side of the uterus * . One of the ovaries produces an egg each month. The egg lies within a sac called a follicle. As the egg matures, the hormone estrogen signals the uterus to prepare for a possible pregnancy by thickening its lining, which is called the endometrium (en-do-MEE-tree-um). If the egg is not fertilized, the extra tissue added to the lining of the uterus is shed from the body. The result is a normal menstrual period.

In most cases, the follicle that released the egg eventually shrinks without causing any symptoms. Functional cysts, however, can develop when the egg is not released normally or the follicle collects fluid or blood after the egg is released. Functional cysts usually look like air bubbles on the ovary when the doctor performs an ultrasound test. There are three basic types of functional cysts:

* that are necessary to maintain a pregnancy if the egg is fertilized. If the egg is not fertilized, the corpus luteum stops producing hormones after about 14 days, breaks down, and gradually disappears. It can, however, also fill with blood or tissue fluid and grow to form a cyst. In most cases, corpus luteum cysts do not cause health problems. They can, however, grow to be as big as four inches in diameter and cause the ovary to twist inside the abdomen, resulting in sudden severe pain. Corpus luteum cysts can also fill with blood and burst during the second half of the menstrual cycle, releasing their blood inside the abdomen and causing severe pain.
  • Hemorrhagic cyst (HEH-muh-rij-ik). Also called a blood cyst, this type of functional cyst develops when a blood vessel in the wall of a cyst breaks and leaks into the cyst. The bleeding may occur rapidly and stretch the wall of the cyst until it bursts, causing pain on one side of the body. The blood in a hemorrhagic cyst forms clots that can be seen on an ultrasound image. If the cyst bursts, the blood is released into the abdominal cavity.
  • Other types of benign ovarian cysts

    There are two other categories of ovarian cysts that are not related to the menstrual cycle but are still considered benign (noncancerous). The first type are dermoid (DERmoyd) cysts (also called ovarian teratomas), which are strange-looking swellings that develop from a cell in the ovary that can give rise to other types of body tissues such as teeth, hair, fatty material, and bone. A dermoid cyst typically contains samples of these other tissues inside its wall. Almost all (98 percent) dermoid cysts are not cancerous. They can, however, cause trouble if they become large enough to cause the ovary to twist and lose its blood supply or if they burst and spill their contents into the abdomen. Dermoid cysts may be as small as one-half inch or as large as 17 inches.

    The second type are endometrioid (en-do-MEET-ree-oid) cysts, which result from endometriosis (en-do-meet-ree-O-sis), a condition that develops when a small patch of tissue from the endometrium—the tissue that lines the uterus—grows inside the ovaries instead of its normal location. The blood in the endometrioid cyst builds up inside the walls of the cyst and eventually turns brown, which is why these cysts are sometimes called “chocolate cysts.” Like other types of ovarian cysts, endometrioid cysts can grow to the point where they rupture and spill their contents onto other abdominal organs. They range in size from three-fourths of an inch to seven or eight inches.

    Pathological ovarian cysts

    The second type of pathological ovarian cyst develops in a polycystic (pol-ee-SIS-tik)-appearing ovary. This condition is not the same as polycystic ovary syndrome (PCOS), even though the names are similar. The word “polycystic” means “many cysts” and refers to the appearance of the ovary on an ultrasound image. A polycystic-appearing ovary is about twice the size of a normal ovary (which is the size of a large olive) and has a number of small cysts that can be seen around the outside of the ovary. The cysts are usually one-half inch in size or smaller and may look like a string of pearls. This type of ovary can be found in some normal women and in some women with various endocrine * disorders. The main difference between a polycystic-appearing ovary and PCOS is that a woman with PCOS will have other symptoms and abnormalities.

    How Common Are Ovarian Cysts?

    Ovarian cysts are common in American women, and 95 percent of these cysts are benign. They can be detected on an ultrasound test in almost all women of childbearing years and in 14 to 17 percent of women after menopause. Most ovarian cysts are functional cysts. Another 10 percent are dermoid cysts. Cancerous ovarian cysts are diagnosed in about 22,000 women in the United States each year. Between 4 and 7 percent of women of childbearing age in the United States are diagnosed with polycystic ovary syndrome.


    Polycystic ovary syndrome (PCOS) is an endocrine disorder that affects between 4 and 7 percent of women in the United States. It is the most common hormonal disorder in women of childbearing age. The most significant features of PCOS are the absence of ovulation and menstruation; acne; abnormal production of androgens (male hormones); growth of hair on the face, chest, and legs; and obesity. The disorder gets its name from the fact that most women with PCOS have polycystic ovaries. It is possible, however, for a woman with normal-appearing ovaries to have PCOS, just as a woman can have a polycystic-appearing ovary without having the disorder.

    The cause of PCOS was not completely known as of 2015, although insulin resistance appeared to be a factor. Women with PCOS cannot have children unless they are treated, and they have an increased risk of type 2 diabetes, high blood pressure, heart disease, and cancer of the uterus. The condition is treated with medications to increase the patient's sensitivity to insulin, to restore ovulation, and to bring on regular menstrual periods.

    Different types of ovarian cysts are more common in different age groups, however. Ovarian cysts in women over 50 or in girls before puberty are more likely to be cancerous than those in women of childbearing age. Dermoid cysts are most common in women in their late 20s or early 30s. Women who take certain types of fertility drugs are more likely to develop corpus luteum cysts than those who do not.

    Who Gets Ovarian Cysts?

    Women from all races and ethnic backgrounds appear equally likely to develop functional ovarian cysts, although Caucasian women are more likely to develop cancerous cysts than women of other races. Some other risk factors for ovarian cysts have been identified and include the following:

    One factor that appears to lower a woman's risk of ovarian cysts is taking birth control pills. The pills work to prevent pregnancy by preventing the production of eggs during ovulation.

    What Are the Symptoms of Ovarian Cysts?

    Most ovarian cysts, including early-stage cancerous cysts, do not cause any noticeable symptoms and are usually found in the course of an ultrasound test performed for other reasons. The most common single symptom that women report is pain in the lower abdomen. The pain is usually described as sharp or stabbing, sudden, and severe. Other symptoms that women may have with ovarian cysts are as follows:

    How Serious Are Ovarian Cysts?

    Most functional ovarian cysts are not a danger to health even though they sometimes cause mittelschmertz or cramping pain in the second half of the menstrual cycle. Functional cysts that continue to grow rather than shrink after a few months may need to be removed to prevent torsion (twisting) of the ovary or to make sure that the cyst is not malignant. In general, cysts that last beyond two to three menstrual cycles or grow larger than 2.5 to 5 inches are removed by surgery. The doctor may also recommend surgery if the cyst is causing severe pain.

    Cancerous ovarian cysts are dangerous, partly because they can grow and develop for some time before causing any obvious symptoms. Although they occur in only 15 women per 100,000 in the United States each year, they cause 14,000 deaths. The five-year survival rate for women diagnosed with the most aggressive type of ovarian cancer is only 17 percent.

    Women who are having any of the following symptoms with ovarian cysts should see their doctor at once:

    How Are Ovarian Cysts Diagnosed and Treated?


    Some ovarian cysts are large enough to be felt when the doctor examines a patient's abdomen in the office or emergency room. Most, however, are too small to be felt during a physical examination but are identified through ultrasound imaging. To perform an ultrasound of the ovaries, the doctor places a thin wand into the vagina and points it in the direction of the uterus and ovaries. This type of ultrasound gives a clearer image of the cyst than an ultrasound performed through the abdomen. The doctor can tell whether the cyst is filled with fluid, is a solid mass, or is a mixture of fluid and solid tissue.

    The doctor may also order magnetic resonance imaging * to confirm the results of the ultrasound or CT scans * to get a clearer picture of the extent of the cyst.

    There are no laboratory tests that can detect ovarian cysts. The doctor may, however, order a urine test to rule out the possibility that the patient has an ectopic pregnancy * and a blood test to check for infection if the patient has a fever.

    A postmenopausal woman with an ovarian cyst will be given a blood test to look for a tumor marker called CA125, a substance in the blood whose level can be measured to evaluate whether a cyst in the ovary is benign or cancerous. It is, however, possible for conditions other than cancer to cause a rise in the level of CA125 in a woman's blood.


    Small benign ovarian cysts that are not causing any symptoms are usually treated first by watchful waiting. Because most functional cysts go away by themselves after a few months, the doctor usually recommends that a woman with a functional cyst return in one to three months for a follow-up ultrasound to see whether the cyst has changed in size. Postmenopausal women are also treated with watchful waiting if the cyst is smaller than an inch, is fluid-filled, and is not causing any other symptoms.

    If ultrasound and other tests indicate that the cyst is very large, is growing, or may be cancerous, the doctor may perform a type of surgery called a laparoscopy * to remove the cyst, or a part of it, from the ovary for examination under a microscope.

    If the cyst is very large, if it is found to be cancerous, or if the woman has completed menopause, the doctor will usually recommend abdominal surgery to remove one or both ovaries. If the cyst is cancerous and the woman is postmenopausal, the doctor may recommend surgical removal of the uterus as well as both ovaries to prevent the cancer from recurring or spreading.

    In some cases the doctor may prescribe birth control pills to regulate the woman's menstrual cycle, to keep follicles from developing into functional cysts, and to stop or slow down the growth of existing functional cysts. Birth control pills also lower the risk of developing ovarian cancer in the future.

    Self-care at home

    Women who have mittelschmertz or mild pain in the lower back or abdomen from ovarian cysts can take over-the-counter pain relievers such as ibuprofen * or acetaminophen * . The doctor may also prescribe pain relievers that contain codeine or oxycodone if the cramps are very bad. Warm baths and heating pads are helpful to many women, and some find that cutting back on coffee and other beverages containing caffeine helps to relieve cramps.

    Can Ovarian Cysts Be Prevented?

    See also Cyst • Menstruation and Menstrual Disorders • Ovarian Cancer


    Books and Articles

    Brody, Jane E. “PCOS: An Infertility Issue That Is Little Understood.” The New York Times. November 24, 2014. http://well.blogs.nytimes.com/2014/11/24/pcos-an-infertility-issue-that-is-little-understood/ (accessed November 24, 2015).

    Parker, Sydney. “When Missed Periods Are a Metabolic Problem.” The Atlantic. June 26, 2015. http://www.theatlantic.com/health/archive/2015/06/polycystic-ovary-syndrome-pcos/396116/ (accessed November 24, 2015).

    Wang, Shirley S. “Infertility, Diabetes, Obesity and the Mystery of PCOS.” The Wall Street Journal. January 27, 2014. http://www.wsj.com/articles/SB10001424052702303553204579346762768385746 (accessed November 24, 2015).


    MedlinePlus. “Ovarian Cysts.” U.S. National Library of Medicine, National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ovariancysts.html (accessed October 26, 2015).

    Merck Manual: Consumer Version. “Noncancerous Ovarian Growths.” http://www.merckmanuals.com/home/women-s-health-issues/noncancerous-gynecologic-abnormalities/noncancerous-ovarian-growths (accessed November 24, 2015).

    Meriggiola, Cristina, and Musa Zumah. “Polycystic Ovary Syndrome (PCOS).” Hormone Health Network. http://www.hormone.org/diseases-and-conditions/womens-health/polycystic-ovary-syndrome (accessed November 24, 2015).

    NHS Choices. “Ovarian Cyst.” National Health Services. (accessed November 24, 2015).

    Office on Women's Health. “Ovarian Cysts.” http://www.womenshealth.gov/publications/our-publications/fact-sheet/ovarian-cysts.html (accessed October 26, 2015).

    Organizations http://www.acog.org (accessed October 26, 2015).

    PCOS Awareness Association. PO Box 88788, Seattle, WA 98138. Website: http://www.pcosaa.org (accessed November 24, 2015).

    PCOS Foundation. 10901 Katy Freeway, Houston, TX 77079. Telephone: 713-487-7267. Website: http://www.pcosfoundation.org (accessed November 24, 2015).

    Society for Adolescent Health and Medicine. 111 Deer Lake Rd., Suite 100, Deerfield, IL 60015. Telephone: 847-753-5226. Website: http://www.adolescenthealth.org (accessed October 26, 2015).

    * menstrual (MEN-stroo-al) refers to menstruation (men-stroo-AY-shun), the discharging through the vagina of blood, secretions, and tissue debris from the uterus that recurs at approximately monthly intervals in females of reproductive age.

    * puberty (PU-ber-tee) is the period during which sexual maturity is attained.

    * ultrasound, also called a sonogram, is a diagnostic test in which sound waves passing through the body create images on a computer screen.

    * mittelschmerz (MITT-el-shmairts) is cramping pain that some women experience at the midpoint in their menstrual cycle when one of their ovaries releases an egg.

    * menopause (MEN-o-pawz) is the end of menstruation.

    * malignant (ma-LIG-nant) refers to a condition that is severe and progressively worsening.

    * benign (be-NINE) refers to a condition that is not cancerous or serious and will probably improve, go away, or not get worse.

    * ovulation (ov-yoo-LAY-shun) is the release of a mature egg from the ovary.

    * uterus (YOO-teh-rus) is the muscular, pear-shaped internal organ in a woman where a baby develops until birth.

    * hormones are chemical substances that are produced by various glands and sent into the bloodstream carrying messages that have certain effects on other parts of the body.

    * endocrine (EN-do-krin) refers to a group of glands, such as the thyroid, adrenal, and pituitary glands, and the hormones they produce. The endocrine glands secrete their hormones into the bloodstream, and the hormones travel to the cells that have receptors for them. Certain hormones have effects on mood and sometimes cause emotional swings.

    * hypothyroidism (hi-po-THY-roydih-zum) is an impairment of the functioning of the thyroid gland that causes too little thyroid hormone to be produced by the body. Symptoms of hypothyroidism can include tiredness, paleness, dry skin, and in children, delayed growth and mental and sexual development.

    * infertility (in-fer-TIH-lih-tee) is the inability of females to become pregnant or of males to cause pregnancy.

    * shock is a serious condition in which blood pressure is very low and not enough blood flows to the body's organs and tissues. Untreated, shock may result in death.

    * magnetic resonance imaging (or MRI) uses magnetic waves, instead of x-rays, to scan the body and produce detailed pictures of the body's structures.

    * CT scans is the shortened name for computed tomography (toMOG-ra-fee), which uses computers to view structures inside the body. Formerly known as computerized axial tomography (CAT).

    * ectopic pregnancy (ek-TAH-pik) is an abnormal pregnancy in which the fertilized egg develops outside the uterus, usually within one of the fallopian tubes.

    * laparoscopy (lap-uh-ROS-kuhpee), also called minimally invasive surgery, is a type of surgery in which a small fiberoptic instrument is inserted through a very small incision to examine the inside of the abdomen or remove small amounts of tissue.

    * ibuprofen (eye-bew-PRO-fin) is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce fever and relieve pain or inflammation.

    * acetaminophen (uh-see-theMIH-noh-fen) is a medication commonly used to reduce fever and relieve pain.

    Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

    (MLA 8th Edition)