Functional Cysts: Description, Symptoms, Causes, Tests and Exams, and Treatments

functional cyst on ovary

Functional ovarian cysts, physiological ovarian cysts, corpus luteum cysts, or follicular cysts are fluid-filled sacs that form on or within an ovary.

This article is about the cysts that usually grows during the monthly menstrual cycle, called functional cysts.


Functional cysts are not the same as cysts caused by cancer or other diseases.

Cysts on the outer layer of the ovary (as opposed to those within the body of the ovary) are cystadenomas. More often than not, these growths are non-malignant (not cancerous).

Serous Cystadenomas are small cysts filled with pale yellow fluid. They usually consist of a single compartment. They rarely give any severe symptoms, unless they burst.

Mucinous Cystadenomas are cysts filled with sticky material. They usually consist of more than one compartment.

They can gradually grow and put pressure on other internal organs, such as the bladder or bowel, so have to be removed. They can also sometimes block the blood supply to an ovary by twisting the ovary, a process known as torsion.

Other growths, such as follicular cysts and dermoid cysts form in the body of the ovary, rather than on the outer layer.

The follicular cysts often disappear of their own accord. Polycystic ovarian syndrome gives rise to many small cysts within the ovaries.

Areas of endometriosis (consisting of the type of tissue that makes up the womb lining) may be found on the ovary, forming so-called “chocolate cysts,” or endometriomas.

Cyst on Ovary Symptoms

Usual signs of ovarian cysts include a dull pain or a swelling in the lower abdomen, frequent urination (if the cyst is putting pressure on the bladder), constipation (if the cyst is putting pressure on the bowels), and discomfort during sexual intercourse.

The symptoms of an ovarian cyst are similar to those of ovarian cancer. Medical tests are needed to distinguish between the two conditions. Endometriomas can give rise to pain and excess bleeding at the time of menstruation.

Torsion of an ovary can cause severe pain in the lower abdomen. Urgent medical attention is needed. Without prompt treatment, the ovary may die.

If a cyst bursts, there is often severe pain in the lower abdomen, sometimes followed by dizziness, rapid breathing, or a fever. Patients need urgent medical attention since severe or even deadly complications can occur.


It is not uncommon for women to get cysts on their ovaries, but it is not clear why one woman gets them and not another. Obesity and smoking seem to be risk factors.

Each month during your menstrual cycle, a follicle (where the ovum is developing) grows in your ovary.

Most months, an egg gets released from this follicle (called ovulation). If the follicle fails to open and release an egg, the fluid remains inside the follicle and forms a cyst, which is called a follicular cyst.

Another type of cyst, called a corpus luteum, occurs after an egg gets released from a follicle. It often contains a small amount of blood.

Ovarian cysts are relatively common and occur more frequently during a woman’s fertile years (from puberty to menopause). These cysts become a rare occurrence after menopause.

Researchers found no specific risk factors.

Functional ovarian cysts are different from ovarian tumors (including ovarian cancer) or cysts due to hormone-related conditions, such as ovarian polycystic oestrus.

Taking drugs for fertility can cause a condition called ovarian hyperstimulation, in which multiple large cysts form in the ovaries. They usually disappear after the woman’s period or after a pregnancy.

Tests and Exams

The specialist doctor may discover a cyst during a physical examination or medical check-ups or when you have an ultrasound scan for another reason.

Ultrasound is done in many patients to diagnose a cyst. Your doctor may need to see you again in 4 to 6 weeks to see if it is gone.

Other imaging tests that may be done when necessary include:

  • CT scan.
  • Doppler flow studies.
  • Magnetic resonance.
  • The specialist doctor may feel the ovarian cyst during a pelvic examination.

The specialist may order the following blood tests:

  • Ca-125 test to look for possible cancer in women who have reached menopause or who have an abnormal ultrasound.
  • Hormonal levels (such as HL, FSH, estradiol, and testosterone).
  • GCH in serum (pregnancy test).

Functional Cysts Treatments

If a cyst is relatively small, a physician may decide to leave it in place. The cyst can be monitored using ultrasound scanning, and removed if it starts to grow significantly.

Although a patient may be keen to have a cyst remove, a physician has to balance the risk of leaving a cyst in place with the threat of surgery.

If a woman still wants to have children, this will have a bearing on the treatment. Surgery may get rid of a cyst but could decrease overall egg production.

Patients often take painkillers, including aspirin, ibuprofen, and acetaminophen (paracetamol), while experts monitor the cyst.

More potent painkillers, such as opioids, may be needed in cases of a burst cyst or torsion of the ovary.

Levonorgestrel-Releasing Intrauterine System (LNG-IUS): This contraceptive device can be used to reduce the pain from an endometrioma. It releases the hormone levonorgestrel in the womb, resulting in lighter periods (they may cease altogether).

Progestin hormones, such as medroxyprogesterone acetate and dienogest, are synthetic analogs of the hormone progesterone. They are often taken to alleviate the symptoms of endometriomas.

Danazol is a drug used to treat endometriomas by preventing ovulation. It can cause side-effects similar to those seen from male hormones, such as acne, deepening of the voice, and unwanted hair growth on the face and chest.

Patients usually require surgery to remove larger cysts, particularly those that are starting to press against nearby organs.

Laparoscopy, or “keyhole surgery,” can be used to get rid of some cysts. Huge cysts may require full abdominal surgery. Nowadays, medical experts can remove even very large mucinous cystadenomas with low risk to the patient.

If experts think that a cyst may be cancerous, they will remove the whole cyst and possibly the ovary as well. Further surgery may be required if examination of the removed tissue confirms that cancer is present.