Ovarian cysts

This page was reviewed under our medical and editorial policy by

Ruchi Garg, MD, Chair, Gynecologic Oncology, City of Hope Atlanta, Chicago and Phoenix

This page was reviewed on November 17, 2021.

In the female reproductive system, ovaries are the two almond-shaped organs on each side of the uterus, where eggs mature and get released. Fluid-filled sacs may form on the ovaries as a normal part of menstruation, during childbearing years or after menopause. Every month during menstruation, at least one small ovarian cyst is likely to form on either ovary, according to the Office on Women’s Health.

Typically, these cysts are harmless, don’t cause any symptoms and go away on their own. It’s rare for an ovarian cyst to be malignant, or cancerous.

However, ovarian cysts may lead to serious symptoms in some circumstances, such as when one ruptures or twists. Large cysts may cause pelvic pain, fullness or heaviness, and bloating in the abdominal region. Women who experience a sudden onset of severe abdominal or pelvic pain with a fever or vomiting should seek medical attention right away.

This article will cover:

Types of ovarian cysts

Functional cysts: These are the most common kind of ovarian cysts that occur as part of ovulation. They typically resolve on their own without treatment in about one to three months. They’re broken down into two types.

  • Follicular cysts: During the menstrual cycle, the ovary releases an egg. Once mature, the egg bursts through the small follicle sac to travel down the fallopian tube. If the follicle doesn’t release the egg, it may continue to grow, forming a cyst.
  • Corpus luteum cysts: After a follicle releases an egg, the empty sac typically shrivels into a lump of cells called corpus luteum. In some cases, the corpus luteum doesn’t shrink—instead, it accumulates fluid and forms a cyst. Though they usually go away over several weeks, they may grow to almost 4 inches in size and may bleed or cause painful twisting of the ovary. Some drugs used in fertility treatments to cause ovulation may increase the risk of corpus luteum cysts.

Dermoid cysts (teratomas): These cysts may contain different types of bodily tissue, such as hair, skin or teeth. They’re often present from birth but may grow in size during childbearing years. Typically, they don’t cause symptoms and aren’t cancerous.

Cystadenomas: Fluid-filled cysts may form on the surface of the ovary. Though they may grow in size, they’re most often benign (noncancerous).

Endometriomas: These cysts form as a result of endometriosis, which occurs when tissues similar to those lining the uterus grow outside the uterus.

Polycystic ovary syndrome: Sometimes, ovaries develop many small cysts, which may cause health issues such as infertility.

Ovarian cancer: Malignant (cancerous) cysts are rare, but when they do occur, they are considered to be ovarian cancer.

Causes of ovarian cysts

The cause of ovarian cysts depends on the type of cyst. They may occur due to slight changes in bodily processes, another health condition or infection.

Hormonal problems or fertility drugs may produce functional cysts, while hormonal birth control may lower the risk. They may also develop early in pregnancy, when the body creates an ovarian cyst as a stop-gap measure before the placenta forms. If the cyst doesn’t go away, it may need to be surgically removed.

Endometriosis is a condition that may lead to an ovarian cyst. With endometriosis, tissue that’s similar to the lining of the uterus begins to form outside of the uterine cavity and may attach to an ovary, forming a growth called an endometrioma. These cysts may be painful during menstruation and sex. Endometriosis is also the most common reason for infertility. 

A severe infection in the ovaries or fallopian tubes may also cause ovarian cysts to develop.

Symptoms of ovarian cysts

While most cysts are small and don’t cause symptoms, others may lead to immediate symptoms.

A corpus luteum cyst, for example, may cause nausea, vomiting and pain if it results in a twisted ovary. Other symptoms include pressure and bloating, swelling, and pain in the abdominal and pelvic areas—often on the side where the cyst is located. Anyone experiencing severe symptoms, or feeling faint, dizzy or weak with rapid breathing, should seek medical attention immediately.

Other side effects aren’t as common but may happen, such as:

  • A dull ache in the lower back or thighs
  • Inability to fully empty the bladder or bowels
  • The need to urinate frequently
  • Painful sex
  • Painful menstruation
  • Weight gain
  • Unusual bleeding
  • Tender breasts
  • Bloating

What does a ruptured ovarian cyst feel like?

A ruptured ovarian cyst may prompt sudden and serious pain in the groin, belly or low back. In rare cases, it may cause some of the symptoms above, such as bloating and unusual bleeding. Reach out to the care team if any of these symptoms occur.

Who gets ovarian cysts?

Each month, most women make one functional cyst—or more. Women with a regular menstrual cycle are more likely to get ovarian cysts. After menopause, however, ovarian cysts are less common. Postmenopausal patients who have an ovarian cyst may be at higher risk for ovarian cancer.

Diagnosing ovarian cysts

For patients experiencing possible symptoms of an ovarian cyst, doctors may order one of the following tests:

  • A pregnancy test helps rule out pregnancy, and a hormone level test may help rule out or diagnose hormone-related issues.
  • An ultrasound image of the pelvis is used to determine whether symptoms such as bleeding and pelvic pain are caused by an ovarian cyst. The test uses sound waves to create pictures of the pelvic organs and detect the location and size of the cyst. It also helps doctors determine whether a mass is fluid-filled, solid or both. Having a complex or solid mass is linked to an increased risk for cancer, a 2018 study in the journal JAMA Internal Medicine found.
  • A CA-125 blood test measures the level of a protein called CA 125. Elevated levels are linked to ovarian cancer, particularly for patients who have gone through menopause.

Treatment of ovarian cysts

Treatment options may include those below:

  • Watchful waiting: Doctors may decide to regularly monitor an ovarian cyst with ultrasound exams.
  • Surgery: Doctors may recommend surgery if they suspect cancer, or if the cyst is large or causing symptoms. Removal of an ovarian cyst is called an ovarian cystectomy, and removal of one or both ovaries is called an oophorectomy. For benign cysts, a minimally invasive surgery done with a scope (laparoscopy) may be recommended. During a laparoscopy, the surgeon makes a small incision in the pelvis, then uses the scope to view and remove the cyst. In more complicated cases—if the cyst is large or cancer is suspected—doctors may need to perform surgery involving a larger incision to the abdomen, called a laparotomy, or open surgery.

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