Follicular cysts are functional or simple, noncancerous cysts that grow in the ovaries. Follicular cysts occur during ovulation, the menstrual cycle phase when a follicle releases an egg from one of the ovaries.

This article discusses symptoms, causes and risk factors, diagnosis, and treatment of follicular cysts.

What Are Follicular Cysts?

Follicular cysts are a type of benign ovarian cyst caused by normal hormonal fluctuations during the menstrual cycle. Usually harmless, these fluid-filled sacs grow on the follicles where the egg develops during the follicular phase of the menstrual cycle.

During ovulation, the follicle releases an egg from one of the ovaries. If the follicle doesn’t rupture (break) and release the egg, a fluid-filled sac, or cyst, forms.

Symptoms

Many women don’t even know they have a follicular cyst because they are usually asymptomatic (without symptoms).

Types of Ovarian Cysts

Ovarian cysts are common, with 20% of women developing at least one in their lifetime.

Ovarian cysts can be simple or complex. Simple cysts, like follicular cysts, tend to be benign, or noncancerous. but complications can occur if the cyst grows in size.

Large cysts can cause rupture, hemorrhaging, or twisting of the ovary, called torsion. In rare cases, complex cysts can be cancerous, and women are at a higher risk after menopause.

Some women may experience mild symptoms, which may include:

  • Abdominal ache
  • Swelling, fullness, or pressure in the abdomen

Causes and Risk Factors

Follicular cysts are common and aren’t caused by underlying conditions or abnormalities. During the menstrual cycle, follicles grow in the ovary. The follicle is responsible for developing the egg and producing estrogen. The increase in estrogen changes the uterine lining to prepare the body for pregnancy. When the egg matures, the follicle releases it during ovulation.

Symptoms of Ovarian Cyst Complications

It is uncommon for simple cysts to lead to rupture, torsion, or hemorrhaging, which can cause more severe symptoms. Severe symptoms may be signs of more than a follicular cyst.

Immediate medical attention is needed for the following symptoms:

  • Sudden, sharp abdominal pain
  • Fever
  • Nausea
  • Painful urination
  • Pain during intercourse
  • Irregular menstruation

Unruptured follicles cause follicular cysts. When the follicle doesn’t rupture and release the egg, it swells up with fluid and forms a cyst.

Risk Factors

Several factors increase the risks of developing follicular cysts, including:

  • Women of reproductive age: Between puberty and menopause, women are more likely to experience follicular cysts.Ovulation: Women who are ovulating are at a higher risk of developing follicular cysts.Fertility drugs: These drugs cause the development of multiple follicles and induce ovulation which can cause a follicular cyst if the follicle remains unruptured.

Diagnosis

More often than not, follicular cysts go undetected and undiagnosed. If a woman is feeling symptoms or goes in for a routine checkup, cysts may be detected through a pelvic exam.

If your healthcare provider suspects you have a cyst, they may recommend the following tests:

  • Transvaginal ultrasound: A wand-like instrument called a transducer is placed inside the vagina to get images showing a cyst’s size, location, and shape.
  • Blood test: A blood test can determine whether a cyst may be concerning.

Treatment

You typically don’t require treatment if you have a small cyst (under 5 centimeters) and are asymptomatic. Follicular and other simple cysts usually go away, or decrease in size, within six to eight weeks without treatment. In the rare case that what you have remains unresolved after several menstrual cycles, you likely do not have a simple cyst, and further testing and treatment may be necessary.

How Often Should You Get a Pelvic Exam?

The American College of Obstetricians and Gynecologists recommends that women see an obstetrician-gynecologist (ob-gyn) at least once a year to get a pelvic exam. However, if you are experiencing symptoms, you should see a healthcare provider sooner.

Watchful waiting may be used to monitor the cysts. You may have repeat ultrasound to monitor their size or appearance.

Generally, the prognosis is good, and the cysts resolve on their own within several menstrual cycles.

Summary

Follicular cysts are a type of simple ovarian cyst. Women of reproductive age tend to get them during the ovulation phase of their menstrual cycle. These cysts are common and do not indicate an underlying medical condition. Often, follicular cysts go undetected and resolve on their own. Women who experience pelvic pain or bloating should talk with their healthcare provider. 

A Word From Verywell

Follicular cysts are a normal occurrence in women of reproductive age during ovulation. If you experience any symptoms, you should speak to your healthcare provider to get a pelvic exam. Although follicular cysts are usually benign, they should be checked out in case treatment is needed.