6 Causes of Enlarged Ovaries: What Your Ultrasound Really Means

• A normal adult ovary is about 2.5–5 cm long with a volume of 5–15 ml; it is generally called enlarged above ~10 ml before menopause and above ~8 ml after menopause.
• The six common causes are PCOS, ovarian cysts, ovarian hyperstimulation after fertility treatment, ovarian torsion, pelvic infection with an abscess, and — rarely — ovarian cancer.
• Most enlarged ovaries in younger women are harmless and many cysts clear up on their own within a few menstrual cycles.
• A transvaginal ultrasound is the best first test; tumour markers like CA-125 and a CT scan are added only when the picture looks concerning.
• Sudden severe one-sided pelvic pain, or persistent bloating and pelvic pressure after menopause, need urgent evaluation — do not wait.
• A single test rarely gives the full answer; doctors combine your age, symptoms, ultrasound features and blood tests before deciding what to do.

A normal adult ovary is roughly the size of a large grape or small walnut — about 2.5–5 cm long, 1.5–3 cm wide, with a volume of 5–15 ml in your reproductive years. After menopause the ovaries shrink to about 1–5 ml.

An ovary is usually called enlarged when its volume goes above about 10 ml before menopause or above about 8 ml after menopause, or when it measures more than 5 cm across. These numbers are guides, not hard rules. Your doctor reads them alongside your age, symptoms, hormone picture, the other findings on the scan, and how things change over time.

Ultrasound is the first and most useful test. A transabdominal scan, done with a full bladder through the lower belly, gives an overall view of both ovaries and the uterus. A transvaginal scan, done with an empty bladder using a slim probe placed in the vagina, gives a much clearer picture of each ovary, the size of any cyst, and its internal structure — so it is the preferred test for a detailed look. In private labs a pelvic ultrasound costs roughly Rs 600–3,500 and it is free at most government hospitals. You can read more about what the scan involves in our guide to transvaginal ultrasound in India.

Certain ultrasound features point toward specific causes. Both ovaries enlarged with a ring of many tiny follicles around the edge (the "string-of-pearls" look) suggests PCOS. A single clear, fluid-filled cyst usually means a harmless functional cyst. A complex cyst with solid parts, thick walls or finger-like projections needs closer attention. A swollen, very tender ovary with reduced blood flow can mean torsion. Your doctor uses these clues to decide what comes next.

PCOS is the single most common reason both ovaries look enlarged in women of reproductive age, and it is especially common in India — affecting roughly 6–22 percent of women depending on how it is measured. On ultrasound the ovaries are bigger than usual with that classic string-of-pearls ring of small follicles.

Doctors diagnose PCOS when at least two of these three are present: irregular or absent ovulation (fewer than nine periods a year or long gaps), signs of high male-type hormones (extra facial or body hair, persistent acne, hair thinning, or raised testosterone on a blood test), and polycystic-looking ovaries on the scan. Insulin resistance, weight gain around the middle and darkened skin folds (acanthosis nigricans) often go along with it. If unwanted facial and body hair sounds familiar, PCOS is worth ruling in or out.

Treatment depends on what matters most to you. Lifestyle change is the foundation — even a 5–10 percent reduction in weight can restart ovulation, lower male hormones and improve insulin resistance. An Indian-friendly approach swaps polished white rice for brown rice or millets like ragi, jowar and bajra, adds whole dals and 2–3 cups of vegetables a day, cuts refined sugar, and builds in about 150 minutes of activity a week.

Medicines are added as needed: combined contraceptive pills to regulate cycles and ease acne and hair growth, metformin for insulin resistance, spironolactone for excess hair, and letrozole or clomiphene to help with ovulation when you are trying to conceive. Our PCOS treatment guide and PCOS fertility guide walk through the options in detail.

Because PCOS raises the long-term risk of type 2 diabetes, high cholesterol and — with very infrequent periods — thickening of the womb lining, ongoing follow-up matters. If your periods are very far apart, your doctor may prescribe a progestin every couple of months to bring on a bleed and protect the endometrium.

Cysts are the second most common reason an ovary looks enlarged. What they mean varies enormously by type, so the words "ovarian cyst" should not be a cause for panic on their own.

Functional cysts are the most common and the most reassuring. They are simple fluid-filled sacs that form as part of the normal cycle, and 7 in 10 clear up on their own within one to three periods. A simple cyst under 5 cm before menopause is usually just watched with a repeat scan in 6–8 weeks. Occasionally one ruptures, causing a sudden but usually short-lived one-sided pain that settles with paracetamol over a few days.

Dermoid cysts (mature teratomas) are benign growths that can contain unusual tissue such as hair or fat. They do not disappear on their own, can grow large and can cause the ovary to twist, so they are usually removed surgically — ideally by keyhole (laparoscopic) surgery that preserves healthy ovary.

Endometriomas, or "chocolate cysts", are pockets of old blood that form when Understanding Endometriosis: Causes, Symptoms & Management tissue grows on the ovary. They can cause painful periods, pain during sex and fertility problems, and are managed with hormones, surgery, or fertility treatment depending on your goals — our endometriosis pain management guide covers this further.

Cystadenomas are benign cysts that can grow very large and cause a bloated, full feeling; they are usually removed and checked under the microscope. A small share of complex cysts turn out to be borderline or low-grade tumours, which is exactly why complex masses are removed and examined rather than simply watched.

To judge risk, doctors use validated ultrasound checklists (the IOTA Simple Rules and ADNEX model) alongside tumour markers and your menopausal status. Simple thin-walled cysts before menopause carry under a 1 percent cancer risk; complex cysts with solid parts carry more, and these are referred onward. For a fuller breakdown see our guides to ovarian cysts and when to worry and to an adnexal (ovarian or tubal) mass.

OHSS is a complication of fertility treatment, where the hormone injections used to grow eggs in IVF cause both ovaries to swell with many follicles and fluid to leak out of blood vessels. Mild forms are common (around 1 in 4 IVF cycles); severe OHSS is uncommon (about 1–5 percent) but needs hospital care.

It happens because the stimulation drugs and the trigger injection prompt the ovaries to release substances that make blood vessels leaky. Fluid then shifts into the abdomen and sometimes the chest while the blood itself becomes concentrated. Becoming pregnant in the same cycle can make OHSS worse and last longer.

You are more likely to develop OHSS if you are young, have a low BMI, have PCOS or many follicles, or have had OHSS before. Symptoms range from mild bloating and discomfort to severe abdominal swelling, breathlessness, reduced urine output and weight gain.

Mild OHSS is managed at home with rest and fluids. Moderate cases are monitored closely; severe cases are admitted for intravenous fluids, drainage of excess fluid if needed, and blood-thinning injections to prevent clots. The best management is prevention — experienced fertility clinics lower the risk by tailoring drug doses, using a different trigger injection, or freezing all embryos to transfer in a later, calmer cycle.

Ovarian torsion is when the ovary twists on the ligaments that carry its blood supply, cutting off its circulation. It is most common when there is already a cyst or mass adding weight, and it can also happen in pregnancy. Without quick treatment the ovary can be permanently damaged within hours, so this is a true emergency.

The classic sign is sudden, severe pain on one side of the lower abdomen — often the worst pain a woman has felt — frequently with nausea and vomiting. The pain may come and go if the ovary twists and untwists. Unlike a ruptured ectopic pregnancy, the woman usually stays stable but is in genuine distress.

Diagnosis combines your symptoms, a pregnancy test (to rule out ectopic pregnancy), and an ultrasound that may show an enlarged ovary with reduced blood flow. Because the scan is not always conclusive, doctors keep a low threshold for keyhole surgery to look directly.

Treatment is urgent laparoscopic untwisting of the ovary, saving it whenever possible — even an ovary that looks dark at first can recover once blood flow returns. Any underlying cyst is usually removed at the same time to stop it happening again. Our guide to ovarian torsion as an emergency explains the warning signs in more detail. If you have sudden severe one-sided pelvic pain, go to a gynaecology emergency the same day — every hour counts.

Pelvic inflammatory disease (PID) is an infection of the upper reproductive tract, usually from sexually transmitted infections such as chlamydia or gonorrhoea travelling up from the cervix. In its more severe form, infection can collect into a pocket of pus involving the tube and ovary — a tubo-ovarian abscess — which shows up as a swollen, tender mass on the scan.

Symptoms include lower abdominal or pelvic pain, fever, abnormal or foul-smelling discharge, pain during sex, and sometimes abnormal bleeding. A pelvic exam is markedly tender. Because PID can be mild or even silent yet still damage the tubes, doctors often start treatment on suspicion rather than waiting for every test.

Diagnosis includes a pregnancy test, transvaginal ultrasound, blood tests, and swabs for chlamydia and gonorrhoea — these tests are free at government STI clinics run under NACO. Mild PID is treated with a course of antibiotics at home; an abscess or severe infection needs hospital treatment with intravenous antibiotics, and larger abscesses may need draining.

Treating your partner is essential to prevent reinfection. Untreated or repeated PID is a major cause of blocked tubes, future ectopic pregnancy and long-term pelvic pain, so prompt care matters. See our guides to pelvic inflammatory disease and STIs and free screening for Indian women.

Ovarian cancer is the rarest cause on this list but the most serious. It accounts for about 4 percent of cancers in Indian women, with roughly 36,000 new cases a year per ICMR. The difficulty is that early symptoms — bloating, feeling full quickly, pelvic pressure, changes in bowel or bladder habits — are vague and easy to dismiss, and there is no reliable screening test for the general population. As a result it is often found late. When caught early, survival is much better, which is why taking persistent symptoms seriously is so important.

Risk is higher with increasing age (most cases are after menopause), a family history of ovarian or breast cancer, inherited BRCA1 or BRCA2 mutations, Lynch syndrome, never having been pregnant, and endometriosis. Protective factors include pregnancy, breastfeeding and years of combined contraceptive pill use. If breast or ovarian cancer runs in your family, our guide to BRCA testing in India explains who should consider genetic testing.

The key message: persistent bloating, early fullness, pelvic pressure or new bowel or bladder changes lasting more than about three weeks — especially after menopause — deserve a proper workup, not a brush-off as "just IBS" or "just menopause". Our detailed guide on early warning signs of ovarian cancer covers the symptoms to watch.

When cancer is suspected, doctors combine a pelvic exam, transvaginal and abdominal ultrasound, the CA-125 (and sometimes HE4) tumour markers, and a CT scan for staging. The diagnosis is usually confirmed at surgery rather than by biopsy beforehand. Treatment at a gynaecological-oncology centre typically involves surgery to remove all visible tumour followed, in most cases, by platinum-based chemotherapy. Much of this care is covered for eligible patients under Ayushman Bharat PMJAY, and India has strong cancer centres including Tata Memorial Mumbai, Adyar Cancer Institute Chennai, AIIMS Delhi, Kidwai Bangalore and RCC Trivandrum.

When a scan shows enlarged ovaries, the next steps depend on your age, symptoms and what the ultrasound looks like. The process is methodical, and most women never need anything beyond the first couple of steps.

First, a careful history and pelvic examination — your age, period pattern, any pain or bloating, fertility history and family history of cancer usually point strongly to one of the six causes.

Second, a good-quality transvaginal ultrasound to characterise the ovaries and apply the IOTA Simple Rules and ADNEX model. If the picture fits PCOS, hormone and metabolic blood tests follow. If there is a complex cyst, its features are described carefully.

Third, tumour markers when appropriate: CA-125, often with HE4 and the ROMA score, in women after menopause or with worrying scan features. An important caution — CA-125 can be raised by many harmless conditions such as endometriosis, fibroids, infection and even a period, so it is never read alone.

Fourth, further imaging only when needed: an MRI to characterise a tricky mass, or a CT scan to stage suspected cancer.

Fifth, referral to the right specialist — gynaecological oncology for anything suspicious, general gynaecology surgery for benign cysts that need removing, a fertility specialist for OHSS, and emergency care for suspected torsion or abscess. Finally, many complex masses are confirmed and treated at the same laparoscopic or open surgery, where tissue can be examined on the spot to guide what is done.

Some presentations of enlarged ovaries need urgent attention rather than a routine appointment. Seek same-day care if you have:

For non-urgent findings, start with a gynaecologist — at a private clinic (consultation roughly Rs 500–2,500) or free at a government district hospital or PHC. They will examine you and arrange the right ultrasound, which costs about Rs 600–3,500 privately or is free in government hospitals.

If a complex mass or possible cancer is found, ask for referral to a gynaecological-oncology unit at a tertiary cancer centre such as Tata Memorial Mumbai, Adyar Cancer Institute Chennai, Rajiv Gandhi Delhi, Kidwai Bangalore, AIIMS, RCC Trivandrum or a major private cancer centre.

For a suspected torsion, abscess or other emergency, go straight to a hospital with round-the-clock gynaecology and an operating theatre. For PCOS-related fertility help, a dedicated fertility centre can guide ovulation induction, IUI or IVF.

On cost: Ayushman Bharat PMJAY covers most ovarian surgery and cancer treatment for eligible families, and state schemes (such as Tamil Nadu, Kerala, Karnataka, Maharashtra and Andhra Pradesh programmes) add further cover. IVF and fertility treatment are usually not covered. If you live far from a tertiary centre, teleconsultation services can offer initial guidance — but the single most important principle is not to let distance delay evaluation of a worrying ovarian finding.

• ACOG — Ovarian Cysts (FAQ)
• NHS — Ovarian cyst
• NHS — Polycystic ovary syndrome (PCOS)
• WHO — Polycystic ovary syndrome
• NHS — Pelvic inflammatory disease (PID)
• ICMR–National Cancer Registry Programme (NCRP)
• RCOG — Ovarian Hyperstimulation Syndrome (patient information)