Ovarian cysts

An ovarian cyst is a sac that develops in or on an ovary. It may contain fluid, blood, thicker material, or a mixture of fluid and solid tissue.

Ovarian cysts are common during the years when you have menstrual periods. Many form as part of normal ovulation, when an ovary releases an egg. These are called functional cysts. They are usually harmless and often disappear within a few menstrual cycles.

Other cysts develop because of conditions such as endometriosis or from cells within the ovary. These may not disappear on their own.

Most ovarian cysts are not cancer. However, a cyst that persists, causes symptoms, has unusual ultrasound features, or appears after menopause may need closer assessment. “Complex cyst” is an ultrasound description, not a diagnosis of cancer. It means the cyst contains features other than clear fluid, such as internal walls, blood, or solid areas.

The importance of a cyst depends on its appearance, size, symptoms, whether you have reached menopause, and how it changes over time.

Many ovarian cysts cause no symptoms. They may be found during an ultrasound or examination performed for another reason.

When symptoms occur, they may include:

• Dull, aching, or sharp pain in the lower abdomen or pelvis
• Pressure, fullness, or bloating
• Pain during sex
• Needing to urinate more often
• Difficulty emptying the bladder or bowels
• Changes in menstrual bleeding

Symptoms alone cannot confirm that you have an ovarian cyst. Pelvic pain and bloating have many possible causes, including bowel, bladder, uterine, and pregnancy-related conditions.

Sudden, severe pain can occur if an ovary twists or a cyst ruptures. A ruptured cyst may release fluid or blood into the pelvis. Some ruptures cause brief pain and settle without treatment, while significant internal bleeding needs urgent care.

Functional cysts develop from the structures involved in ovulation.

A follicular cyst may form when the follicle holding an egg does not open normally. A corpus luteum cyst can develop after the egg is released if the remaining follicle seals and fills with fluid or blood. A blood-filled functional cyst is sometimes called a haemorrhagic cyst.

Other types include:

• Endometriomas, caused by endometriosis tissue growing on an ovary
• Dermoid cysts, also called mature teratomas, which arise from reproductive cells and may contain fat or other tissue
• Cystadenomas, which grow from cells on the ovary’s surface
• Benign, borderline, or cancerous ovarian tumours that contain cystic areas

Factors linked with certain ovarian cysts include being of reproductive age, pregnancy, endometriosis, previous ovarian cysts, and medicines that stimulate ovulation. A cyst found after menopause is less likely to be functional and is usually assessed more carefully.

Polycystic ovary syndrome, or PCOS, is different from having one large ovarian cyst. In PCOS, the ovaries may contain many small, immature follicles alongside hormone and ovulation changes.

A clinician will ask about your pain, menstrual cycle, pregnancy possibility, previous cysts, and other symptoms. A pelvic examination may identify tenderness or a mass, but it cannot reliably confirm what the mass is.

A pelvic ultrasound is the main imaging test. A transvaginal ultrasound uses a slim probe placed in the vagina to obtain detailed images. An abdominal ultrasound may also be used, particularly if a cyst is large or a transvaginal scan is unsuitable.

The scan can show the cyst’s size and whether it is simple, blood-filled, or complex. It also helps distinguish an ovarian cyst from a mass arising elsewhere in the pelvis.

Depending on the situation, assessment may also include:

• A pregnancy test, because ectopic pregnancy can cause similar symptoms
• Blood tests to look for anaemia, infection, or tumour markers
• A repeat ultrasound to see whether the cyst disappears or changes
• MRI or other imaging when ultrasound findings are unclear

CA-125 is a blood marker sometimes used when ovarian cancer is a concern, especially after menopause. It cannot diagnose cancer by itself. Endometriosis, menstruation, pregnancy, fibroids, and other non-cancerous conditions can also raise it.

If a cyst is removed, examination of the tissue in a laboratory provides the most definite information about its type.

Treatment is based on your symptoms, age, menopause status, ultrasound findings, and the cyst’s size and growth.

For a simple cyst that looks harmless, watchful waiting may be appropriate. This means monitoring symptoms and, when needed, repeating the ultrasound after an agreed period. Many functional cysts resolve without treatment.

Pain relief may help while a cyst is being monitored. Use over-the-counter medicines only as directed and check whether they are suitable for you, particularly if you are pregnant, have kidney or stomach problems, take blood thinners like warfarin or apixaban, or use other medicines.

Hormonal contraception can reduce the formation of some new functional cysts by stopping ovulation. It does not reliably make an existing functional cyst disappear faster. Hormonal treatment may also be used as part of managing endometriosis, but it is not suitable or necessary for everyone.

Surgery may be considered when a cyst:

• Is causing ongoing or severe symptoms
• Is large, growing, or persistent
• Has concerning ultrasound features
• May have twisted, ruptured, or caused significant bleeding
• Cannot be confidently identified without tissue testing

Many cysts can be removed through laparoscopy, or keyhole surgery. Larger or more concerning masses may require open abdominal surgery.

A cystectomy removes the cyst while preserving ovarian tissue where possible. Sometimes the affected ovary must also be removed. Surgical planning may consider future fertility, menopause status, symptoms, and the possibility of cancer. If cancer is suspected, assessment by a gynaecological cancer specialist may be recommended.

Most ovarian cysts do not cause complications.

Ovarian torsion happens when an ovary twists around the tissues supporting it. This can reduce or stop its blood supply. It often causes sudden one-sided pelvic pain, commonly with nausea or vomiting, and usually needs emergency assessment.

A cyst can also rupture. A mild rupture may cause pain that settles with observation and pain relief. Heavy internal bleeding can cause worsening pain, weakness, dizziness, fainting, a rapid heartbeat, or pale and clammy skin.

Large cysts may press on the bladder or bowel. Some cysts can damage ovarian tissue or require removal of an ovary, but many people remain fertile with one healthy ovary. Endometriomas and the underlying endometriosis may affect fertility in some people.

A minority of ovarian cysts are cancerous. The concern is higher after menopause and when imaging shows solid areas, irregular internal structures, increased blood flow, or other suspicious findings. These features still require specialist interpretation rather than self-diagnosis.

Most ovarian cysts cannot be completely prevented. Functional cysts are linked with normal ovulation, while dermoid cysts and cystadenomas are not caused by lifestyle choices.

Hormonal contraception may lower the chance of developing new functional cysts because it can suppress ovulation. It is not routinely appropriate for everyone and does not prevent every type of ovarian cyst.

Treating endometriosis may reduce symptoms and, in some circumstances, lower the chance of an endometrioma returning after surgery. It cannot guarantee that another cyst will not form.

There is no recommended screening test for ovarian cysts in people at average risk who have no symptoms. Regular ultrasound screening can find harmless changes and does not by itself prevent complications or ovarian cancer.

If you have a functional cyst, it may disappear over several weeks or a few menstrual cycles. A follow-up scan may be used to confirm that it has resolved. Not every small, simple cyst needs repeated imaging.

Persistent cysts may remain stable for months or years without causing harm. Others grow, change in appearance, or begin causing symptoms and then need further assessment. The monitoring plan is usually influenced by ultrasound findings and whether you have reached menopause.

Keep track of significant changes in pain, bleeding, bloating, bladder symptoms, or how quickly you feel full when eating. Persistent symptoms deserve review even if a previous cyst appeared harmless, because they may have another cause.

Cysts can recur, especially functional cysts and endometriomas. Having had one cyst does not mean that every future episode of pelvic pain is another cyst.

Most people with benign ovarian cysts continue their usual work, exercise, relationships, and family plans. If a cyst is large or painful, a clinician may advise temporary changes to strenuous activity or sex because movement can worsen pain and may raise concern about twisting. There is no single restriction that applies to every cyst.

Removal of one ovary does not usually cause menopause if the other ovary is healthy. Fertility outcomes are more individual when both ovaries are affected, ovarian tissue has been damaged, or endometriosis is present.

Arrange a routine appointment if you have pelvic pain, persistent bloating, pain during sex, new urinary pressure, or menstrual changes that do not settle. Follow-up is also important if a previously identified cyst is being monitored or your symptoms have changed.

Seek urgent same-day medical advice for new or worsening pelvic pain, especially if you also have fever, vomiting, unusual bleeding, or could be pregnant. Pelvic pain or bleeding during pregnancy needs prompt assessment because an ectopic pregnancy can have similar symptoms.

Go to an emergency department or call emergency services if you have:

• Sudden, severe pelvic or lower abdominal pain
• Severe pain with repeated vomiting
• Fainting, marked dizziness, confusion, or severe weakness
• Pale, cold, or clammy skin
• Rapid breathing or a racing heartbeat with severe pain
• Heavy bleeding or signs of shock

These symptoms can occur with ovarian torsion, significant internal bleeding, or another urgent abdominal condition.

Can an ovarian cyst go away on its own?

Yes. Many functional cysts disappear without treatment within several weeks or menstrual cycles. Endometriomas, dermoid cysts, and cystadenomas are less likely to resolve by themselves.

What size ovarian cyst needs surgery?

There is no single size that always requires surgery. Decisions also consider symptoms, ultrasound appearance, growth, menopause status, and the risk of twisting or cancer. A smaller suspicious cyst may need treatment, while some larger simple cysts can be monitored.

Does an ovarian cyst mean I have cancer?

Usually not. Most ovarian cysts are benign, especially before menopause. Further assessment is more important when a cyst appears after menopause, persists, grows, or has concerning ultrasound features.

Can ovarian cysts affect my periods or fertility?

Functional cysts can sometimes delay or alter bleeding. Most cysts do not prevent pregnancy. Endometriosis, ovarian damage, or surgery involving both ovaries may have a greater effect on fertility.

Can I exercise or have sex with an ovarian cyst?

Many people can continue normal activities if they feel comfortable. A large or painful cyst can make vigorous movement or sex uncomfortable. Ask about temporary restrictions if your cyst is large, you have significant pain, or torsion is a concern.

Can an ovarian cyst cause weight gain?

A large cyst can cause abdominal swelling or a feeling of fullness, but most cysts do not cause major weight gain. Persistent abdominal enlargement, appetite changes, or unexplained weight change should be assessed rather than assumed to come from a cyst.