The ovaries are an important part of the female reproductive system. Sitting either side of the uterus (womb), they release an egg once every 28 days as part of the menstrual cycle. Once an egg is released, the follicle in which it formed bursts and shrinks ready for the next cycle to begin. If the follicles do not correctly shrink after the egg is released, a fluid filled sac, called a cyst, can develop in the ovary. 1 in 10 ovarian cysts also involve growth into the fallopian tubes and other nearby organs. Ovarian cysts can also form on the outside of the ovary, from a group of abnormal cells that would otherwise create the eggs, which is less common.

Ovarian cysts are often non-cancerous (benign), cause no symptoms, and disappear without the need for treatment. However, this is not always the case. They can be painful and grow up to the size of a large melon before they rupture (burst) or begin to shrink. They can block the blood supply to the ovaries, or cause internal bleeding. Some ovarian cysts can be cancerous and lead to ovarian cancer, which is most common in post-menopausal women.

Women of reproductive age are most likely to suffer from ovarian cysts. However, they can occur in young children as well as elderly women. Many women have them and never know anything about it. However, due to the risks associated with their growth, its worth speaking to your doctor if you believe you have a cyst.

To determine whether your symptoms are a result of an ovarian cyst, your GP can carry out an ultrasound. A blood test can be taken to determine if any cancer is present, and a test will be taken to determine whether hypothyroidism (under-active thyroid) is the cause as this affects which treatments are suitable.

What are the Symptoms of Ovarian Cysts?

What does it feel like when you have a cyst on your ovary? Ovarian cysts usually don't cause any symptoms and they gradually disappear within a few months, meaning you never even realise you had them. However, this is not always the case. They may be visible to your doctor during a routine examination such as a smear test. If they get big enough or rupture (burst), they can cause abdominal pain, pelvic pain and bloating which is hard to ignore.

Symptoms of Ovarian Cysts

  • Lower abdominal, back and pelvic pain - The pain can be severe and sharp in a small location, or a longer lasting dull sensation over a wider area.
  • Pain during sex
  • Constipation and pain in your bowels
  • Urge incontinence
  • Heavy (menorrhagia) or lighter periods that normal
  • Painful periods (dysmenorrhea)
  • An irregular pattern to your periods
  • Vaginal bleeding - Outside of your normal periods.
  • Abdominal bloating
  • Feeling full after eating just a little
  • Difficulty conceiving - Fertility is unaffected in most women, but in some it can make it difficult (not impossible) to conceive.

Symptoms of Ovarian Cancer

Most ovarian cysts are benign (non-cancerous). However a small number are malignant (cancerous), and need to be treated to avoid ovarian cancer advancing. Ovarian cancer affects 5-17% of postmenopausal women, and is much rarer in women before the menopause.

The symptoms of ovarian cancer are often more severe and persistent than felt with benign ovarian cysts. With most women complaining of the following:

  • Persistent abdominal bloating
  • Feeling full and/or loss of appetite
  • Lower abdominal and pelvic pain
  • Urge incontinence

Conditions with similar symptoms to ovarian cysts are endometriosis, pelvic infection, fibroids and even menstruation in some women. If you notice any changes and are experiencing any of the symptoms listed above, you should speak to your GP.

What Causes Ovarian Cysts?

Cysts can occur on and in any part of the body. They can appear on the surface of your skin as a round lump which may contain pus. They can appear behind the knees as a Baker's cyst, often caused by a sports injury. Ganglion cysts develop near joints and tendons from leaked fluid from the joint or tendon. Bone cysts occur naturally as fluid fills holes in bones. In all cases, they are usually painless and go away by themselves unless they become infected.

Ovarian cysts are not caused by any external factor; there is nothing you have done to make you more likely to develop ovarian cysts. They are often caused by hormonal changes or other pelvic health conditions.

  • Menstruation and issues with ovarian follicles - The most common type of ovarian cysts form during the menstrual cycle. When the egg doesn't leave the ovary properly as it gets stuck in the follicle. Or if the follicle keeps hold of its fluid and doesn't shrink after the egg is released. The follicle then swells and becomes a functional cyst. These cysts are usually simple, harmless and benign (non-cancerous), containing fluid behind a thin wall. They rarely require treatment and go away themselves after a few months.
  • Menstruation and issues with the cells that produce eggs in the ovary - The cells that produce the eggs within the ovary can develop complex dermoid cysts. These are often more solid and contain hair, fat, blood and thick fluid.
  • Menopause - Ovarian cysts are not always related to the menstrual cycle. They can also develop just before and following the menopause. In this situation they are called pathological cysts. These form as a result of abnormal cell growth, of the cells used to create the eggs, or the cells on the outside of the ovary. These cysts are also often benign (non-cancerous), however malignant (cancerous) cysts are most common in women that have been through the menopause.
  • Endometriosis - During endometriosis, the endometrium lining normally found on the inside of the uterus, grows on the outside of the uterus and on the other pelvic organs. This tissue can sometimes form blood-filled cysts on the ovaries called endometrioma.
  • Polycystic ovary syndrome (PCOS) - This condition causes lots of ovarian cysts to develop. They are often small and harmless, and the result of egg follicles not growing to full ovulation due to inadequate hormones.
  • Hereditary - If you have a close family member that has suffered from cancer, you are at an increased risk of developing ovarian cancer.
  • Cancer - Ovarian tumours are growths of cells on the ovary. Not all ovarian tumours are cancerous, most of the time they are benign and harmless.
  • Hypothyroidism (under-active thyroid) - If you suffer from hypothyroidism, where you have a slow metabolism due to less thyroid hormone being produced, you are vulnerable to developing ovarian cysts. This is because the hormones of the reproductive system are also affected.

To read about other causes of pelvic pain, visit the Causes and Diagnosis of Pelvic Pain page.

How to Treat Ovarian Cysts

Few ovarian cysts require treatment as they often go away on their own. Because of this, if you are found to have ovarian cysts, you will likely be monitored without treatment to begin with.

  • If your cyst is simple and under 5cm in diameter, it is unlikely that you or your doctor will be aware of it. No treatment is usually required.
  • If your cyst is simple and measures 5-7cm in diameter, your doctor will book an ultrasound scan in 12 months to ensure it has gone away. They may also take a blood test to ensure it is benign (non-cancerous).
  • If your cyst is simple and measures over 7cm in diameter, your doctor may arrange further tests such as an MRI to ensure it will not cause further issues. If your cyst is likely to rupture, you may be admitted to hospital to monitor its development.
  • Any cyst in a post-menopausal woman will be more closely monitored, as the risk of their cyst turning cancerous is much higher.
  • If you are pregnant and have ovarian cysts, you will also be closely monitored. They will likely disappear during the pregnancy. Surgery will be avoided during pregnancy.

If your symptoms are negatively affecting your quality of life and your cysts are very large and/or likely to rupture, your doctor may recommend one of the treatments below.

Treating Ovarian Cysts

  • Treat the cause - If your cysts are a result of another condition, such as endometriosis or hypothyroidism, treating it can resolve your cysts. It can also prevent them recurring.
    • Thyroid hormone replacement therapy - If you are suffering with hypothyroidism, even if you have large ovarian cysts, a daily does of Levothyroxine (daily oral tablet of L-T4) can reduce the cyst over 6 months where it eventually disappears.
  • Transabdominal aspiration and injection of methotrexate - This procedure includes the aspiration (emptying) of the fluid within a cyst, guided by an ultrasound. The cyst is then injected with methotrexate which is an immune suppressant commonly used to treat arthritis. It is a successful treatment for simple and endometrioma cysts (cysts that are related to endometriosis). The procedure can be performed under general or local anaesthetic and you go home the same day. It may need to be repeated but usually no more than 3 times before the cyst permanently disappears.
  • Surgery - If you have persistent large cysts which are cancerous, or likely to become cancerous, you may be offered surgery to remove them, the ovaries, uterus and surrounding tissue. 80% of ruptured cysts are also treated with emergency surgery. IMPORTANT: Surgery to remove ovarian cysts risks damage to your ovaries which can leave you infertile. Your surgeon will aim to reduce any damage and, if necessary, take only one ovary. If you have heavy bleeding, severe pain, a fever, dark smelly vaginal discharge or abdominal swelling during your recovery from surgery, you may have an infection.
    • Laparoscopy - A keyhole surgery through the abdomen, where the cysts is cut and removed.
    • Laparotomy - An open surgery, also through the abdomen. Preferred for the removal of larger cysts. This procedure is often more painful with a slower recovery.

Myths About Treating Ovarian Cysts

  • The combined oral contraceptive pill will help - FALSE! There is no evidence that taking the combined oral contraceptive pill will make a cyst go away more quickly. Although there is some evidence that they prevent cysts occurring to begin with.
  • The fluid can be removed to resolve the cyst - FALSE! The cyst will likely fill up again. Fluid will only be removed to aid diagnosis and to allow for medicine to be injected.

To read about other treatments available for pelvic pain, visit our pelvic pain treatment page.


Abduljabbar, H. S. Bukhari, Y. A. Al Hachim, E. G. Ashour, G. S. Amer, A. A. Shaikhoon, M. M. Khojah, M. I. (2015). Saudi Med J. Review of 244 cases of ovarian cysts. [online] 36(7), p834-838. [viewed 14/06/18]. Available from:

Arthritis Research UK. (2015). Methotrexate: Drug Information. [online] Arthritis Research UK, 2015. [viewed 15/06/18]. Available from:

Dharmshaktu, P. Kutiyal, A. Dhanwal, D. (2013). Endocrinology, Diabetes and Metabolism Case Reports. Vanishing large ovarian cyst with thyroxine therapy. [online] 11 2013, EDM130050. [viewed 15/06/18] Available from:

Gupta, P. Huria, A. (2016). Nigerian Medical Journal : Journal of the Nigeria Medical Association. Management of ovarian cysts with percutaneous aspiration and methotrexate injection. [online] 57(1), p19-23. [viewed 15/06/18]. Available from:

Kim, J. H. Lee, S. M. Lee, J-H. Jo, Y. R. Moon, M. H. Shin, J. Kim, B. J. Hwang, K. R. Lee, T. S. Bai, K. M. Jeon, H. W. (2014). Public Library of Science One. Successful Conservative Management of Ruptured Ovarian Cysts with Hemoperitoneum in Healthy Women. [online] 9(3), e91171. [viewed 15/06/18]. Available from:

NHS Choices. (2016a). Ovarian cyst: Causes. [online] NHS Trust, 2016. [viewed 25/05/18]. Available from:

NHS Choices. (2016b). Ovarian cyst: Overview. [online] NHS Trust, 2016. [viewed 25/05/18]. Available from:

NHS Choices. (2016c). Ovarian cyst: Treatment. [online] NHS Trust, 2016. [viewed 25/05/18]. Available from:

NHS Choices. (2017). Skin cyst. [online] NHS Trust, 2017. [viewed 15/06/18]. Available from:

Royal College of Obstetricians and Gynaecologists. (2013). Information for you: Ovarian cysts before the menopause. [online] Royal College of Obstetricians and Gynaecologists, 2013. [viewed 25/05/18]. Available from:

Royal College of Obstetricians and Gynaecologists. (2016). The Management of Ovarian Cysts in Postmenopausal Women. [online] Royal College of Obstetricians and Gynaecologists, 2016. [viewed 25/05/18]. Available from:

Sharma, Y. Bajpai, A. Mittal, S. Kabra, M. Menon, P. S. (2006). Journal of Pediatric Endocrinology and Metabolism. Ovarian cysts in young girls with hypothyroidism: follow-up and effect of treatment. [online] 19(7), p895-900. [viewed 15/06/18]. Available from:

Shu, J. Xing, L. Zhang, L. Fang, S. Huang, H. (2011). Reproductive Biology and Endocrinology : RB&E. Ignored adult primary hypothyroidism presenting chiefly with persistent ovarian cysts: a need for increased awareness. [online] 9, p119. [viewed 15/06/18]. Available from:

Thyroid UK. (2015). Hypothyroidism. [online] Thyroid UK, 2015. [viewed 15/06/18]. Available from: