Ovarian cysts are fluid-filled sacs or pockets within or on the surface of an ovary. They typically occur as the result of ovulation (the release of an egg from the ovary) and are common in women of childbearing age (from puberty to menopause). Most cysts are normal and shrink over time, usually within one to three months.

Cysts that develop due to normal ovulation are called functional cysts, because they are not related to disease. Other less common types of ovarian cysts include dermoid cysts, cystadenoma cysts and endometrioma cysts. These abnormal ovarian cysts are usually benign, but they may require treatment.

Most ovarian cysts are small and do not causes symptoms. When symptoms are present, the most common is pain or a sense of fullness or pressure in the lower abdomen or pelvis. This may be caused by:

• Rupture of the cyst
• Rapid growth of the cyst
• Twisting of the cyst around its blood supply

Ovarian cysts are usually diagnosed during routine pelvic exams, although ultrasounds are sometimes necessary. Blood tests, pregnancy tests and biopsies may also be performed to rule out other conditions.

Most cysts are functional cysts and disappear within 60 days without any treatment. Therefore, a physician is likely to monitor a patient over one to three months to determine whether the cyst has changed in size or caused increased symptoms. A physician may recommend surgery to remove the cyst if the patient is postmenopausal as cysts that develop after menopause (a rare occurrence) can increase the risk of ovarian cancer. Surgery may also be recommended if the cyst:

• Does not disappear after several menstrual cycles
• Has gotten larger
• Looks unusual on the ultrasound
• Causes pain

Women who frequently develop cysts may have polycystic ovarian syndrome (PCOS), a hormonal disorder that causes women to develop many small cysts in their ovaries. These women, as well as others who frequently develop cysts may be prescribed birth control pills, which prevent ovulation and the formation of cysts.  However, not all recurring ovarian cysts indicate this condition and not all women with PCOS develop ovarian cysts.

Ovarian cysts cannot be prevented in women who are ovulating. However, most cysts do not cause symptoms, are not cancerous and disappear without treatment. Regular gynecological exams are a good way to help ensure that changes in the ovaries are detected and diagnosed as early as possible.

Most ovarian cysts are fluid-filled sacs or pockets within or on the surface of an ovary. They occur as the result of normal ovarian functions, including ovulation (the release of an egg, called ovum, from the ovary) and hormone production. Because these cysts are produced from normal ovarian function, they are called functional cysts. 

These fluid filled sacs are commonly referred to as simple cysts, and are almost always benign. Cysts that are solid or contain both solids and fluids (known as complex cysts) might not always be benign and require further investigation.

The ovaries are two organs about the size and shape of an almond located on each side of a woman’s uterus. Eggs develop and mature in the ovaries and are released in monthly cycles during a woman’s childbearing years (from puberty to menopause). Each month, a woman’s ovary grows tiny cysts (follicles) that hold the eggs. The follicles nourish eggs with fluids. When an egg is mature, the sac breaks open so the egg can travel through the fallopian tube for fertilization.

The sac is now called a corpus luteum cyst and persists to secrete hormones that support an early pregnancy. If a pregnancy does not occur, the cyst dissolves and stops producing hormones. It is this drop in hormone levels that brings on menstruation.

The most common type of ovarian cysts occurs when the sac does not break open and continues to grow (failure of ovulation) or when the sac does not dissolve after fertilization does not occur. Functional cysts, which form as a normal part of ovulation, usually resolve on their own. Abnormal cysts are less common and usually benign, but in rare cases they may be cancerous.

Many women develop cysts at some time during their lives. Most are harmless and cause little or no discomfort. Oftentimes, women may be unaware of their presence. Cysts usually disappear without treatment within a few months. However, they can produce serious symptoms, particularly if they rupture (or burst).

Women who ovulate regularly tend to develop more ovarian cysts, since functional cysts are by far the most common. Therefore, cysts are less common in women who do not ovulate regularly, such as menopausal women or those taking birth control pills (which work, in part, by preventing ovulation).

Ovarian cysts can also develop during pregnancy and may cause painful cramping. More than one egg each month can be produced in the ovary, but usually only one egg will develop to maturity. The remaining egg may result in an ovarian cyst. Additionally, some cysts can fail to dissolve and persist during pregnancy causing complications.

It is important to note that ovarian cysts are different from a condition called polycystic ovarian syndrome (PCOS). In PCOS, multiple small follicles grow and form a very characteristic appearance on ultrasound (called polycystic ovaries). Most women with PCOS fail to ovulate, leading to a hormonal imbalance that can cause multiple symptoms, such as male-pattern hair growth (hirsutism), oily skin, menstrual irregularities and difficulty getting pregnant (infertility). However, not all women with PCOS develop ovarian cysts and not all ovarian cysts are a sign of PCOS.

There are different types of ovarian cysts. Functional cysts, which develop as a normal part of ovulation, are by far the most common type of ovarian cyst.

Each month a woman’s ovaries grow cyst-like structures called follicles or sacs. When an egg matures, the follicle breaks open to release the egg, which travels through the fallopian tube for fertilization. The sac is now called a corpus luteum cyst and persists to secrete hormones that support an early pregnancy. If a pregnancy does not occur, this cyst dissolves and stops producing these hormones. It is this drop in hormone levels that brings on menstruation.

Functional cysts are a product of normal ovarian function. There are two main types of functional cysts: 

• Follicular cyst. Develops before ovulation. These cysts are usually harmless, rarely cause pain and often disappear on their own within two to three menstrual cycles.
  
  
• Corpus luteum cyst. Develops after ovulation. Fluid can accumulate inside the sac, causing the cyst to grow, sometimes reaching up to 4 inches (10 centimeters) in diameter and can bleed into itself or twist the ovary, causing pain. If the cyst fills with blood, it can rupture, causing bleeding internally as well as a sudden, sharp pain.

A third type of follicle-related cyst, called theca luteum cyst, can develop during pregnancy but is quite rare. It may become quite large but also disappears on its own in most cases.

Polycystic ovaries is a term used to describe the enlarged ovaries with multiple, follicular cysts that sometimes form in women with polycystic ovarian syndrome (PCOS). To be considered polycystic, an ovary must have at least 12 follicular cysts in the range of ¼ to ½ inch (0.6 to 1.3 centimeters) in diameter. Not all women with PCOS develop polycystic ovaries.

There are other types of ovarian cysts, which are abnormal and much less common. They are usually benign but may be cancerous in some cases. They include:

• Dermoid cysts. Made of different kinds of tissue, such as skin, hair, fat and teeth. They are rarely cancerous, but can become large and twist the ovary causing pain. Ovarian cells can produce hair, teeth and other tissues that become part of the forming cyst.
  
  
• Cystadenoma cysts. Develop from cells on the outer surface of the ovary and are often filled with a watery fluid or thick, sticky gel. They can become large – 12 inches (30 centimeters) or more in diameter – and cause pain. They are divided into groups called serous or mucinous cystadenomas, depending on certain characteristics.
  
  
• Endometrioma cysts (also called chocolate cysts because they are filled with dark, reddish-brown blood). Endometrioma 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. They can be painful during menstruation and sexual intercourse.

There are no known risk factors for the most common form of ovarian cysts – functional cysts. The cause of these cysts depends on the type of functional cysts:

• Follicular cysts. Some time during the menstrual cycle, the brain’s pituitary gland releases a large amount of luteinizing hormone (LH). This hormone tells the sac to release the egg. Normally, the egg bursts out of the sac and moves down the fallopian tube for fertilization. If the LH surge does not occur, the sac will not rupture. This traps the egg and starts the development of a cyst. Follicular cysts may be associated with a condition called polycystic ovarian syndrome (PCOS). However, not all women with PCOS develop these cysts.
  
  
• Corpus luteum cysts. When LH does surge and the egg is released, the ruptured sac (now called a corpus luteum) helps prepare the body for conception by producing large amounts of the hormones estrogen and progesterone. If conception does not occur, the cyst normally dissolves, which stops the production of hormones. The drop in hormone levels is the body’s signal to begin menstruation. Sometimes, the sac does not dissolve and the opening seals off. Fluid accumulates inside the sac, causing the corpus luteum to expand into a large, sometimes symptom-causing cyst.

There are also no known risk factors for abnormal cysts, with the exception of endometrioma cysts. Women with endometriosis are at higher risk of developing endometrioma cysts.

Most ovarian cysts are small and do not causes symptoms. When symptoms are present, the most common is pain or a sense of fullness or pressure in the lower abdomen or pelvis. The pain can be sharp, intermittent, sudden in onset and severe. It may be caused by:

• Rapid growth of the cyst. This puts pressure on the ovaries causing pain.
  
  
• Rupture of the cyst. A large cyst is associated with moderately severe, sharp, boring and constant pain that increases while the cyst enlarges to the point of rupture.
  
  
• Twisting of the cyst around its blood supply. A twisted ovary can be severely painful as the blood supply to the ovary diminishes.

Other symptoms may include:

• Abdominal bloating or distention
  
  
• A dull ache in the lower back and thighs
  
  
• Pelvic pain during movement or sexual intercourse
  
  
• Painful or irregular menstrual periods, including a lengthened or shortened menstrual cycle or an absence of menstruation (amenorrhea)
  
  
• Weight gain
  
  
• Nausea
  
  
• Breast tenderness
  
  
• Problems passing urine completely
  
  
• Pain during bowel movements

Patients experiencing the following symptoms should seek medical attention immediately because they could indicate a potential emergency:

• Severe abdominal pain
• Fever
• Vomiting
• Rapid breathing
• Weakness
• Cold, clammy skin

Because ovarian cysts do not cause symptoms, they are usually found during routine gynecological exams. This usually begins with a complete medical history, including menstrual history and a list of current medications. A pelvic exam will be performed, during which a physician may be able to feel the swelling of the cyst on an ovary.

If abnormalities are detected, other tests may be performed, including:

• Ultrasound. Uses sound waves to make “pictures” of organs in the body. An ultrasound can be performed either through the abdomen or vagina (called transvaginal ultrasound) and lasts about 30 minutes. With an ultrasound, a physician can see how the cyst is shaped, its size and location and whether it is fluid-filled, solid or mixed.
  
  
• Pregnancy test. A blood or urine test conducted to rule out pregnancy. Hormone levels (such as LH, FSH, estradiol and testosterone) are tested to evaluate for associated hormonal conditions.
  
  
• CA-125 test. A blood test to determine whether a cyst may be cancerous by measuring a protein called CA-125. A normal CA-125 level is less than 21. The amount of this protein may be higher if a woman has ovarian cancer.
  
  However, the CA-125 is not always an accurate way to determine whether a woman has ovarian cancer. Some ovarian cancers do not make enough CA-125 to be detected by the test. Also, there are noncancerous diseases, such as endometriosis and uterine fibroids that increase CA-125 levels. These tests are usually done only on women over age 35 that are at a high risk for cancer and have a cyst that is partially solid. Because this test is not always accurate, it is currently not recommended as a screening test for ovarian cancer.

Surgical removal of the cyst is sometimes necessary. If this occurs, a biopsy of the cyst tissue is often performed to determine whether it is cancerous.

Since most functional cysts disappear within 60 days without any treatment, a physician is likely to monitor a patient over one to three months to determine whether the cyst has changed in size. This is a common practice for women of childbearing age who have no symptoms and have a simple fluid-filled cyst. It may also be an option for some postmenopausal women.

For patients who frequently develop functional cysts, physicians may prescribe birth control pills to prevent ovulation. This lowers the chance of forming new cysts.

Surgery to remove the cyst may be recommended if any of the following conditions exist:

• The patient is postmenopausal
• The cyst does not disappear after several menstrual cycles
• The cyst has gotten larger over several cycles
• The cyst looks unusual on the ultrasound
• The cyst causes pain

There are two main surgical procedures to remove cysts or treat ruptured cysts:

• Laparoscopy. Surgery in which a lighted instrument, called a laparoscope, is inserted through a small incision into the abdomen to view organs. It may be used if the cyst is small and looks benign on the ultrasound. This procedure is done using general anesthesia. If the cyst is small and looks benign, it can be removed.
  
  
• Laparotomy. Surgical opening of the abdomen. It may be used to remove a large or suspicious cyst. While the patient remains under general anesthesia, a biopsy is conducted on the removed cyst to determine whether the cyst is cancerous. If it is cancerous, the physician may need to remove the ovary (oophorectomy) and other tissues that may be affected, such as the uterus or lymph nodes.

Cysts that form during pregnancy may be treated by surgery. Unless the cyst is cancerous, surgery is usually postponed until after the 12^th week of pregnancy, because the cyst may be producing hormones vital to the pregnancy. These cysts often disappear spontaneously. However, surgery may be necessary before the 12^th week if a cyst continues to enlarge or is tender to the touch.

Ovarian cysts cannot be prevented in women who are ovulating. However conditions that prevent ovulation, such as the use of birth control pills, pregnancy and menopause, reduce the risk of developing cysts.

Regular pelvic exams are a good way to help ensure that changes in ovaries are diagnosed as early as possible. It is recommended that patients also monitor menstrual cycles for abnormalities.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor or other healthcare professional the following questions about ovarian cysts:

1. How will I know if I have an ovarian cyst?
   
   
2. What are the chances that it will disappear on its own?
   
   
3. If I develop an ovarian cyst, am I at risk for developing them again?
   
   
4. How will I know if a cyst has burst?
   
   
5. Do I have polycystic ovarian syndrome (PCOS)?
   
   
6. What type of tests might I need for my condition?
   
   
7. What will these tests tell you?
   
   
8. Should I use birth control pills to prevent ovarian cysts?
   
   
9. How will I know if my condition is a medical emergency?
   
   
10. Will ovarian cysts affect my ability to become pregnant?
    
    
11. If I have ovarian cysts, does it mean my daughters will also develop them?