Ovarian cysts

Ovarian cysts are fluid filled sacs which can develop either inside or on the surface of the ovaries.
There are a number of different types of ovarian cyst, most of which are non-cancerous, and many of which clear up on their own without treatment.

There are two principal types of ovarian cyst. The most common type is ‘functional ovarian cysts’ which develop as part of the menstrual cycle; they are usually harmless and short-lived. Much less common are ‘pathological ovarian cysts’ which are the result of abnormal cell growth.

Most ovarian cysts are non-cancerous but some, more commonly in women who have been through the menopause, can be cancerous.

Functional ovarian cysts are very common and are linked to the menstrual cycle and the formation of eggs within the ovaries. Each egg is formed inside a follicle which contains a fluid to protect the egg as it grows. Sometimes when a follicle doesn’t release a fully grown egg, or it retains the fluid after the egg is released, the follicle can swell and become a cyst. These cysts are usually benign (non-cancerous) but can sometimes cause pelvic pain.

Pathological ovarian cysts are not related to the menstrual cycle so can occur in women before and after the menopause. The cysts are caused by the abnormal growth of the cells used to create eggs or the cells of the outer part of the ovary. These cysts can sometimes grow large, or burst, and potentially block the supply of blood to the ovaries. Pathological cysts are usually benign (non-cancerous), but a small number are cancerous.

Ovarian cysts can also sometimes be the result of an underlying condition, such as endometriosis, where small pieces of the womb lining (the endometrium) are found outside the womb (in fallopian tubes, ovaries, bladder, bowel, vagina or rectum). This tissue can sometimes form blood-filled cysts.

Another condition, polycystic ovary syndrome (PCOS), can causes numerous harmless cysts to develop on your ovaries. These small cysts are caused by egg follicles that don’t reach ovulation, as a result of abnormal hormone levels.

Ovarian cysts normally only cause symptoms if they are very large, if they rupture, or if they block the blood supply to your ovaries.

If any of these occur, your symptoms could include:

  • pelvic pain, ranging from dull heaviness to a sudden sharp and severe pain
  • pain during sexual intercourse
  • a need to urinate frequently
  • difficulty emptying your bowels
  • abnormally heavy or light periods, or irregular periods
  • bloated abdomen and/or feeling full after eating very little
  • sometimes, a difficulty getting pregnant

If your doctor suspects ovarian cysts, you may be referred to have an ultrasound scan. If an ovarian cyst is diagnosed, it may need to be monitored over a few weeks or months by successive ultrasound scans to determine if treatment is required.

MRI scan

MRI (magnetic resonance imaging) is a special technique that uses powerful magnets, radio waves and computers to produce detailed images (or scans) of the inside of your body.


An ultrasound is an imaging procedure used to examine a wide range of parts of your body. 

Gynaecological laparoscopy

A gynaecological laparoscopy is a form of keyhole surgery used to diagnose problems within the pelvis such as your ovaries, uterus, and fallopian tubes.    

Ovarian cyst removal

Ovarian cysts are fluid-filled sacs which develop around the ovaries. They are relatively common, rarely malignant (cancerous) and frequently disappear on their own without treatment. However, large or persistent ovarian cysts, or those that cause unwanted symptoms, may need to be surgically removed.

What next?

If you are suffering with a suspected condition, you should seek the advice of your doctor who will be able to refer you to Benenden Hospital for diagnosis and treatment.

There are four ways to access treatment at Benenden Hospital which include self-funding, using private medical insurance or your Benenden membership, or through the NHS e-Referral scheme.