An ovarian cyst is a sac of tissue that develops inside an ovary. It is very common, usually painless and will often go away without treatment.
Ovarian cysts can affect women of any age.
Most ovarian cysts are small, although some may reach a large size. There are two main types:
- Functional ovarian cysts (the most common type). These are harmless cysts that are short-lived and formed as part of the menstrual cycle.
- Pathological cysts. These are growths in the ovaries that are either benign (harmless) or malignant (cancerous).
See Causes, above, for more information on the different types of ovarian cyst and how they are formed.
What are cysts?
Cysts are fluid-filled sacs that can grow in any part of the body. They can vary in size and content.
Some cysts are solid and may be called tumours (pathological cysts). This does not mean they are cancerous (tumour is just the medical name for a swelling).
Do they cause problems?
Most ovarian cysts are small, benign and do not produce any symptoms.
Larger cysts may cause problems, such as pain and swelling in your abdomen (see Symptoms, above, for more information).
What is the treatment?
Most ovarian cysts disappear after a few weeks without treatment.
If the cyst is large or is causing symptoms, it will probably be removed (see Treatment).
Continue to next section: Symptoms of ovarian cysts