Enlarged ovaries: what does it mean, what causes it and when should you see a doctor?

Enlarged ovaries refers to an increase in the volume of one or both ovaries. This may be a temporary and harmless change that occurs, for example, during ovulation or in early pregnancy – but it can also point to conditions such as ovarian cysts, polycystic ovary syndrome (PCOS), endometriosis or other gynaecological problems.

Many women only discover that they have 'enlarged ovaries' through a gynaecological ultrasound scan – and naturally, the first reaction is fear that it might be something serious. In most cases, however, it isn't. While this change obviously shouldn't be ignored, it often has a harmless, temporary cause that either resolves on its own or responds well to treatment. So how do you know whether everything is normal or whether further investigation is needed? Let's look in more detail at the most common causes of enlarged ovaries and when it's wise to see a doctor.

What does it mean to have enlarged ovaries? 

First, let's clarify what enlarged ovaries actually means.

During the reproductive years, a normal ovary is usually around 3–5 centimetres in length. The size can fluctuate slightly and naturally over the course of the menstrual cycle. For example:

• Before ovulation, the ovary containing the dominant follicle may be slightly larger.
• In early pregnancy, the ovary may temporarily increase in volume because of the corpus luteum.
• After the menopause, the ovaries naturally shrink and their activity decreases.

When the normal size of the ovaries changes and they reach a greater volume than would be expected for your age and reproductive stage of life, this is referred to as enlarged ovaries.

The term is not a diagnosis in its own right; it describes a finding from a gynaecological examination or an ultrasound scan. So there's no reason to panic straight away. In most cases the cause is harmless.

A finding of enlarged ovaries must always be considered alongside other symptoms and investigations in order to reach a clear diagnosis. If the volume remains persistently increased, or if you experience pain, bloating, unusual bleeding or other symptoms, your doctor may recommend additional tests to pinpoint the cause.

Causes of enlarged ovaries 

The causes of enlarged ovaries may be physiological, in other words entirely normal – but there are also more serious causes that require treatment or monitoring. Your doctor will never view ovarian enlargement as an isolated symptom, but will always assess it in the context of your symptoms, your age, your medical history and the ultrasound findings.

Ovulation (a physiological, normal cause)

During the menstrual cycle, one of the ovaries develops a dominant follicle containing the egg. For this reason, that ovary may temporarily increase in size around ovulation. After ovulation, the corpus luteum forms, which can also keep the ovary slightly enlarged for a short time.

This change is entirely normal, no cause for concern and requires no treatment – unless you suffer from painful ovulation or other worrying symptoms arise.

Ovarian cysts

One of the most common causes of enlarged ovaries is ovarian cysts. Most of these are functional, developing over the course of the menstrual cycle and disappearing on their own within a few weeks or months. However, if your doctor finds a large cyst, or cysts that aren't resolving, these need to be monitored – as they can cause lower abdominal pain, bloating or an increased risk of ovarian torsion.

Polycystic ovary syndrome (PCOS)

In patients with polycystic ovary syndrome (PCOS), the ovaries contain numerous small follicles that fail to mature. As a result, they can reach a greater volume than normal and are frequently the cause of enlarged ovaries.

The condition is often accompanied by irregular periods, excess androgens and disrupted ovulation – which is why it is frequently associated with female infertility. That doesn't mean pregnancy is impossible, however. With the right treatment and medical support, many women with PCOS go on to conceive and give birth to healthy babies.

Endometrioma (endometriosis)

An endometrioma is a type of ovarian cyst caused by endometriosis. If you're not yet familiar with endometriosis: it's a condition in which tissue similar to the lining of the womb grows outside the uterus. It is often accompanied by severe period pain, pain during intercourse and difficulty conceiving, and can lead to enlargement of the ovary.

Ovarian torsion (emergency)

Ovarian torsion occurs when the ovary twists around the ligaments supporting it, cutting off its blood supply. This is a medical emergency presenting with sudden, severe lower abdominal pain, nausea and vomiting – without prompt treatment, the ovary can be irreversibly damaged.

Ovarian hyperstimulation syndrome (OHSS)

Ovarian hyperstimulation syndrome can occur following hormonal stimulation of ovulation, as commonly used in assisted reproduction.

In this case, the ovaries enlarge because a large number of follicles mature at the same time. In mild forms you'll only experience bloating and abdominal discomfort, but severe forms may require specialist treatment. According to studies, the classic symptoms of OHSS include nausea, vomiting, bloating, abdominal pain, tachycardia, tachypnoea and dyspnoea.

Pelvic inflammatory disease (adnexitis)

Adnexitis, or infections affecting the uterus, fallopian tubes and ovaries, can cause inflammation and enlargement of the ovaries. Alongside lower abdominal pain, you may experience fever, unusual vaginal discharge and pain during intercourse. Early, appropriate treatment is important to reduce the risk of infertility and chronic pelvic pain.

Pregnancy (including ectopic pregnancy)

In early pregnancy, the ovary that released the egg may remain temporarily enlarged – due to the corpus luteum, which produces progesterone until the placenta takes over this function. This phenomenon can also occur in an ectopic pregnancy.

Importantly, though: an ectopic pregnancy can cause severe lower abdominal pain and, if the fallopian tube ruptures, can become life-threatening – so it requires immediate medical assessment and emergency treatment.

Benign tumours and ovarian cancer

Less commonly, enlarged ovaries can have more serious causes, such as benign tumours or ovarian cancer. The medical literature lists benign causes of ovarian enlargement including luteomas, tumours such as mature cystic teratomas, fibrothecomas and cystadenomas, as well as other rare conditions including capillary haemangioma and massive ovarian oedema.

As a rule, most ovarian findings are not malignant. However, if the ultrasound shows suspicious features, or if you suffer from persistent bloating, an increase in abdominal girth, ongoing lower abdominal pain or other unusual symptoms, your doctor may recommend further investigations.

Even if the suspicion is confirmed and a tumour is indeed the cause, there's no reason to panic immediately. The earlier cancer is detected, the more effectively it can be treated and the better the chances of recovery. The crucial thing is not to ignore the symptoms.

Symptoms of enlarged ovaries 

Enlarged ovaries don't always cause symptoms. Patients are often symptom-free, and the enlargement is discovered incidentally during a routine gynaecological examination or an ultrasound carried out for another reason.

When symptoms do occur, however, they are closely linked to the cause of the enlargement. Most commonly, women notice:

• A feeling of pressure or pain in the lower abdomen
• Bloating
• An irregular menstrual cycle or changes to your periods
• Pain during intercourse
• Frequent urination, if the enlarged ovary presses on the bladder

Enlarged ovaries after the menopause: when it's more concerning 

Once the menopause begins, the ovaries normally shrink and cease their activity. That's why an enlarged ovary or a newly appeared ovarian finding at this stage of life is always a warning sign and requires gynaecological assessment.

Although many findings are benign, the risk of ovarian cancer increases with age. If your ovaries are enlarged after the menopause, your doctor will therefore recommend further tests to establish a diagnosis.

When you should see a doctor immediately

Lower abdominal pain, fever, vomiting, nausea and unusual bleeding are undoubtedly warning signs whenever they occur. They are not among the typical symptoms of enlarged ovaries, but they can appear when there's a more serious underlying cause.

They may indicate ovarian torsion, a ruptured ovarian cyst or an ectopic pregnancy – situations requiring emergency treatment. Seek medical help immediately, therefore, if you experience the following:

• Sudden, very severe lower abdominal pain
• Nausea and vomiting accompanying the pain
• Fever or chills
• Fainting, severe dizziness, marked weakness

How the diagnosis is made: which tests are carried out 

The first step is always the gynaecological examination. When you speak with your doctor, you can describe your symptoms, your cycle pattern and any known pre-existing conditions.

The basic investigation for assessing the ovaries is a transvaginal ultrasound. This allows enlarged ovaries to be evaluated and cysts or other findings to be identified. Depending on the suspected diagnosis, your doctor may then additionally recommend:

• Hormone tests, if PCOS or another endocrine disorder is suspected
• A pregnancy test, if pregnancy is a possibility
• Blood tests to detect infection, if adnexitis is suspected

• The CA-125 tumour marker, particularly in post-menopausal women or if an ovarian finding on ultrasound shows suspicious features.

  

Treatment: it depends on the cause 

There is no single, standard treatment for enlarged ovaries. The approach depends on the cause identified by your doctor, the accompanying symptoms and the test results.

Since functional ovarian cysts often disappear on their own, for instance, they are simply monitored with regular ultrasound checks, without further treatment.

For polycystic ovary syndrome, treatment may involve lifestyle changes and hormone therapy – depending on the patient's symptoms and goals.

In more serious cases such as ovarian torsion, a ruptured cyst or certain ovarian tumours, surgery may be necessary.

The key point is this: treatment options differ from case to case and should always be decided together with your gynaecologist. So if you know your ovaries are enlarged, have the cause investigated and discuss with your doctor whether treatment is needed.

Frequently asked questions about enlarged ovaries

We hope that after reading this article you feel a little reassured – even if you haven't experienced this situation yourself. If you've been told your ovaries are enlarged and you still have questions about symptoms or treatment, you'll find answers to the most common queries below.

What does it mean to have enlarged ovaries?

Enlarged ovaries describes a situation in which one or both ovaries have a greater volume than would be expected for your age and reproductive stage of life. The change may have normal causes, such as ovulation, or stem from conditions such as ovarian cysts, PCOS or endometriosis.

How big are ovaries normally?

In women of reproductive age, an ovary is normally around 3–5 cm long. Bear in mind, though, that ovarian size varies according to age, cycle phase and stage of life – during ovulation or pregnancy, the volume can increase temporarily.

Is it dangerous if my ovaries are enlarged?

Not always. Enlarged ovaries often have harmless, temporary causes, such as a dominant follicle or a functional cyst. However, if they remain enlarged or if pain, unusual bleeding or other atypical symptoms develop, you should arrange a gynaecological examination as soon as possible.

Why is only one ovary enlarged?

An ovarian cyst, an endometrioma, a larger follicle before ovulation or other findings affecting just one ovary are common causes of one-sided enlargement.

Do enlarged ovaries affect fertility?

The enlargement itself is not associated with infertility, but certain causes are. Polycystic ovary syndrome, for example, can disrupt ovulation and make conception more difficult. Likewise, endometriosis – another common cause of enlarged ovaries – can affect fertility.

Can I have enlarged ovaries during pregnancy?

Yes. In the first weeks of pregnancy, the ovary that released the egg may remain temporarily enlarged because of the corpus luteum – a structure that produces the progesterone needed to sustain the pregnancy.

Which tests are carried out for enlarged ovaries?

The most important investigation is an ultrasound, usually transvaginal, which allows your doctor to assess the ovaries and any findings. Depending on the situation and the suspected diagnosis, your doctor may also recommend hormone tests, a pregnancy test, tests for infection or the CA-125 tumour marker.

Do enlarged ovaries resolve on their own?

Sometimes they do – the ovaries can return to their usual size if the cause is temporary, such as ovulation or a functional cyst. If the enlargement is due to a condition such as endometriosis, PCOS or a persistent finding, your doctor will monitor the ovaries so that any changes are detected early.

When do I need to see a doctor immediately?

Seek medical help immediately if you know your ovaries are enlarged and you suddenly develop severe lower abdominal pain, nausea, vomiting, fever, fainting or intense dizziness. Such symptoms may indicate ovarian torsion, a ruptured cyst or an ectopic pregnancy and may require surgery.

Are enlarged ovaries more concerning after the menopause?

After the menopause, the ovaries normally shrink. An increase in volume is therefore unusual and should be medically assessed to rule out a tumour. Many ovarian findings are benign, but at this age it's particularly important to establish the cause and have the recommended tests carried out as early as possible.

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