Ovarian cysts

An ovarian cyst is a sac of fluid on or inside an ovary. Most are harmless, and many go away without treatment. Finding one doesn’t mean you need surgery. What happens next depends on how it looks, your symptoms and whether you’ve been through menopause.

Functional cysts and other types

The most common cysts are called functional cysts, because they form as part of the menstrual cycle. A follicle is a small sac where an egg grows. If it doesn’t open to release the egg, fluid can stay inside and form a follicular cyst. A corpus luteum cyst forms after an egg has been released.

Other types form in different ways. Endometriomas are linked to endometriosis. Dermoid cysts grow from cells that have been there since birth. Cystadenomas can contain watery fluid and grow large. Ask which type your clinician thinks you have and how that affects your follow-up. The word “cyst” covers several different types.

A functional cyst is not the same as polycystic ovary syndrome (PCOS). Cysts linked to the menstrual cycle are separate from hormone conditions such as PCOS. If you’ve been told about both, ask your clinician to explain each one.

What symptoms can lead to a scan

Many cysts cause no symptoms. Others cause discomfort in the pelvis, bloating, pain during sex, or pressure on the bowel or bladder. Book an appointment if you have bloating that won’t go away, feel full quickly or have pain that keeps coming back. These symptoms have several possible causes, so a clinician needs to check them.

An ultrasound scan helps show a cyst’s size, where it is and whether it holds fluid or has solid parts. The scan may use a probe placed inside the vagina. Depending on the check, a clinician may also arrange blood tests or a pregnancy test. Ask what each test can tell you and when you’ll get the results.

Monitoring and treatment

Watching a cyst may mean having another scan to see if it has gone or changed. Surgery is more likely to come up if a cyst stays, grows, causes symptoms or has features that need a closer look. After menopause, there’s a higher chance a cyst is cancer, and the check takes this into account. Most ovarian cysts are not cancer.

If functional cysts keep coming back, you may be offered the contraceptive pill to lower the chance of new ones. It doesn’t shrink a cyst you already have. Your pharmacist, GP or doctor can advise about your options, pain relief and what suits you. Follow medicine leaflets and any prescription instructions.

If surgery is recommended, ask whether they plan to remove only the cyst or whether an ovary may need to come out too. Most cysts don’t affect your chance of getting pregnant. But the cause of the cyst and the operation can matter. Talk about whether you want a pregnancy in future before agreeing to surgery, even if you’re not planning one now.

Pain that needs help now

A cyst can burst (rupture), or an ovary can twist, which is called torsion. Twisting can cut off the ovary’s blood supply. Sudden severe pain in the pelvis, often with feeling sick or vomiting, can be a sign of these problems. A burst cyst can sometimes cause bleeding inside the body.

Call 999 now (UK) or 911 (US), or your local emergency number, for pain in your pelvis that is severe or getting worse, or comes with feeling faint, difficulty breathing or heavy vaginal bleeding. Don’t wait for a follow-up scan, or assume the pain is from a cyst that’s already being watched.

Get help today from NHS 111 or an urgent GP service (UK), or your doctor or urgent care service (US or elsewhere), for tummy pain with nausea or vomiting. Do the same for pain in your pelvis if you are or could be pregnant, or if the pain comes with a very high temperature or feeling hot, cold or shivery. Use emergency care if the pain is severe or you feel faint. The NHS page on cysts says sudden severe pain needs urgent care. Its wider advice on pelvic pain says severe pain needs emergency care. For severe symptoms, follow the emergency advice.

Book a GP appointment (UK), or see your doctor (US or elsewhere), for pain in your pelvis that keeps coming back, bloating that won’t go away, or feeling full quickly. At a follow-up appointment, ask which changes mean you should call sooner and who to contact between scans.