Ovarian cysts

Learn about what ovarian cysts are, the different types of cyst, how they're diagnosed and treated.

What is an ovarian cyst?

Ovarian cysts are fluid-filled sacs or solid pockets that can form in or on your ovaries. The ovaries are two small organs, each the size and shape of an almond. They’re found in the pelvis, in the lower part of your abdomen (tummy). The ovaries store eggs and form part of the female reproductive system. Within ovaries are follicles, which form eggs and release one every month until you go through the menopause.  

Most ovarian cysts are benign (not cancerous). But up to 1 in 10 women will need an operation for an ovarian cyst at some point in their lives. Anyone born with ovaries can develop an ovarian cyst. 

Types of ovarian cyst

A cyst may be described as: 

  • Simple – a fluid-filled cyst with a thin wall 
  • Complex – a cyst that contains thicker fluid or blood, walls within the cyst (septations) or solid areas. 

The type of cyst you have can be different depending on whether you have gone through the menopause or not.  

Simple cysts 

Simple cysts are the most common type of ovarian cyst. They can develop in both those who have gone through the menopause and those who haven’t. Simple cysts are non-cancerous and can develop and disappear without the need for treatment.  

Functional cysts 

A functional cyst is a type of simple cyst. If you haven’t gone through the menopause, you may have a functional cyst. They most commonly develop in women of childbearing age. This is usually from when your periods begin until the menopause when your periods stop.  

Functional cysts can develop if a follicle doesn’t release an egg (you don’t ovulate) or if the fluid that has been protecting the egg in the follicle doesn’t burst and shrink when the egg is released.

Complex cysts 

Complex ovarian cysts include: 

  • Cysts caused by endometriosis, known as endometriomas. This is a condition where the lining of the womb (endometrium) grows outside of the womb. This may be in the ovaries, the fallopian tubes (tubes that the eggs released from the ovaries travel through to the womb) or elsewhere in the pelvis (in the lower part of your tummy).  
  • Dermoid cysts, which develop from germ cells in the ovary. These are the cells that develop into eggs. 

How are cysts diagnosed? 

Ovarian cysts are common. Research suggests simple cysts are found in up to 17 per cent of women. Often an ovarian cyst won’t have symptoms (particularly simple cysts) and may develop and disappear without you being aware of it. They can often be found during gynaecological investigations (of the female reproductive system) for other reasons. They can also be found when having investigations for something unrelated.  

Ovarian cysts can cause similar symptoms to ovarian cancer. If you're experiencing any symptoms of an ovarian cyst, your GP may send you for an ultrasound scan to look at your ovaries. 

An ultrasound is the most common way of scanning for ovarian cysts. Scans such as MRI (a scan that uses magnetic and radio waves) and CT (a scan that uses x-ray) can also be used to gather more information. 

You may need more investigations to check the cyst and work out whether you need any treatment. The type of investigations you might have depend on whether you have gone through the menopause or not. 

What tests can I have to investigate a cyst?  

Blood tests including a CA125 blood test can help your doctor work out if a cyst is cancerous. Your GP may offer you a CA125 blood test if you have a complex cyst (with blood or solid tissue in it). If you have a cyst after going through the menopause or if you are over 50, you will be offered a CA125 blood test as it’s more likely that the cyst could be cancerous. 

The result of your CA125 blood test and ultrasound scan will be combined with other factors, including whether you've been through the menopause, to work out the chance of the cyst being cancerous. It’s unlikely that tests will suggest the possibility of cancer. But if they do, you’ll be referred to a gynaecological cancer specialist for further tests. A team of specialists will review your test results to decide what treatment you may need. They are called a multi-disciplinary team (MDT).  

If you haven’t gone through the menopause and have a simple cyst less than 5cm in size, you may not need further investigation. If you’ve gone through the menopause and the cyst measures less than 1cm, you’re also not likely to need any further investigation. 

You may or may not have symptoms of an ovarian cyst. You might feel worried if you’re experiencing symptoms, but it’s unlikely to be ovarian cancer. However it’s still important to discuss any abdominal (tummy) symptoms with your GP. 

Treating ovarian cysts 

How your cyst is treated will depend on:  

  • the type of cyst 
  • your age 
  • your symptoms  
  • your medical and family history.  

Most simple cysts will disappear on their own.  

It’s not necessary to remove all ovarian cysts with surgery (an operation). This form of treatment is only considered if the cyst could be cancerous, or if it's large and could cause complications or uncomfortable symptoms.  

You may have regular ultrasounds and blood tests over the course of a year to check the cyst if you have a certain type of cyst, or if you've been through the menopause. Most people are discharged from follow up after a year as long as there is no change in the size or appearance of the cyst. 

Surgery for ovarian cysts 

Surgery to remove the cyst is sometimes needed. This is the best way of finding out exactly what the type of cyst you have as specialist pathologists (experts in diseases) will examine it.  

Different operations are used to remove ovarian cysts:  

  • Keyhole surgery (a laparoscopy) is used to remove most cysts. This operation is where small cuts are made in your tummy.  
  • Open surgery (a laparotomy) is used to remove larger cysts. A larger cut is made in your tummy during the operation. 

Surgery is carried out under general anaesthetic (where you're given medicine to send you to sleep). 

The type of operation you have will depend on the appearance of the cyst and whether you’ve gone through the menopause. The different types of operation are: 

  • Removing the cyst only (cystectomy)  
  • Removing the ovary, fallopian tube and cyst (unilateral salpingo-oophorectomy) 
  • Removing both fallopian tubes, both ovaries and the cyst (bilateral salpingo-oophorectomy). 

If you need an operation your doctor will talk to you about it in detail before it happens. 

It’s unlikely that your test results will suggest the possibility of cancer. But if ovarian cancer is suspected you will be offered a different operation to remove the cancer

Further information 

NHS has more information about diagnosing and treating ovarian cysts.

Royal College of Obstetricians & Gynaecologists has more information about ovarian cysts before the menopause.

Last reviewed: August 2022

To find out more about our review process, take a look at our information standards.