Symptom · Ovarian cysts
Most cysts are nothing. Some deserve a proper look.
Ovarian cysts are extremely common through the reproductive years and into perimenopause — most are simple functional cysts that resolve on their own. The two things worth knowing well: which cysts warrant follow-up, and the different rules that apply after menopause (any new ovarian cyst deserves careful assessment). This page is the plain-English map: what's normal, what's not, and what to ask for.
Educational · not medical advice
'Ovarian cyst' is a catch-all for any fluid-filled sac on or in the ovary. Most are functional — the ovary makes them every cycle as part of ovulation, and they disappear again within weeks. Others are structural (dermoid cysts, endometriomas from endometriosis, cystadenomas). In perimenopause, erratic ovulation means functional cysts turn up more often and sometimes get bigger before they resolve, which is why so many midlife women get sent for a scan and then reassured. The rules change after menopause: the ovaries aren't ovulating any more, so a new ovarian cyst is not a functional cyst and warrants proper characterization. The point of this page is to help you tell the difference and know what to ask for — not to scare you into surgery you don't need, and not to leave you dismissing a red flag.
Why this is happening now
Cysts are common, and 'cyst on the ovary' is not one thing. Knowing which kind matters more than the word itself.
- 01
Functional cysts — the normal ones
Follicular cysts (the follicle grows but doesn't release the egg) and corpus luteum cysts (the follicle releases but doesn't collapse) are part of normal ovulation. They are usually simple (thin-walled, clear fluid), typically under 5cm, and resolve within 1–3 cycles without treatment. Perimenopause makes these more common because ovulation is more erratic.
- 02
Endometriomas — 'chocolate cysts'
Cysts on the ovary from endometriosis. They have a characteristic ground-glass appearance on ultrasound and can cause deep pelvic pain, painful sex, and painful periods. They are benign but they can grow, distort pelvic anatomy, and affect fertility. Management is a specialist endo conversation — surgery isn't automatically the answer.
- 03
Dermoids, cystadenomas, and other benign structural cysts
Dermoid cysts (teratomas) are made of a mix of tissues; cystadenomas are fluid-filled and can get large. Both are almost always benign but often need removal because they can twist (ovarian torsion — a genuine emergency), rupture, or keep growing. They are not caused by anything you did.
- 04
'Polycystic-appearing ovaries' is not the same as an ovarian cyst
In PCOS/PMOS the ovaries have many small immature follicles giving a 'polycystic' appearance on scan. Those are not cysts in the sense of a mass that needs monitoring — they're a hormonal picture. If a scan report says 'polycystic-appearing ovaries' and you don't have PCOS symptoms, ask what specifically was seen; if you do, cross to the PCOS guide.
- 05
After menopause the rules change
The postmenopausal ovary should not be actively making follicles. Any new ovarian cyst after 12 months of no periods is not a functional cyst and needs proper characterization: transvaginal ultrasound (ideally with a risk-of-malignancy score like IOTA/O-RADS), CA-125, and gynaecology review. Most post-menopausal ovarian cysts are still benign — but 'wait and see' isn't the right first move.
- 06
Ovarian torsion — the one true emergency
A cyst (usually 5cm+) can cause the ovary to twist on its blood supply. The presentation is sudden severe one-sided pelvic pain, often with nausea and vomiting. This is an emergency — the ovary can be lost if it isn't untwisted within hours. Sudden severe unilateral pelvic pain with a known cyst warrants an emergency-room trip, not a wait-and-see.
What actually happens with a cyst
Most cysts need watching, not treating. A few need a plan. The point is a proper look, not automatic surgery.
Simple functional cyst — repeat scan in 6–12 weeks
Standard care: an initial ultrasound; if it looks simple and under 5cm, a follow-up scan after a couple of cycles to confirm it has resolved. Most do. No treatment needed in between beyond over-the-counter pain relief if it aches.
Larger or complex cyst — CA-125 and a risk score
For cysts that are bigger, complex on ultrasound, or persistent, a CA-125 blood test and a formal risk-of-malignancy calculation (IOTA/O-RADS, or in the UK the RMI score) helps triage whether it's likely benign or needs a gynae-oncology opinion. CA-125 alone is a rough tool — it goes up with endometriosis, fibroids, and menstruation — so it's read in context, not in isolation.
Endometrioma — treated as endometriosis, not just 'a cyst'
If the scan looks like an endometrioma, the conversation shifts to endometriosis management: hormonal suppression, pain control, and specialist surgery only where there's a clear reason (pain, growth, fertility). Ovarian tissue is precious; surgery on endometriomas can reduce ovarian reserve, so it's a specialist decision.
Post-menopausal cyst — characterize before deciding
Transvaginal ultrasound with a risk score, CA-125, and gynaecology referral. Most small simple cysts (under ~5cm, purely fluid, thin-walled) in postmenopausal women are followed rather than removed. Complex, solid, or larger cysts warrant a proper surgical opinion — but that opinion should include the option of removing only the affected ovary rather than both.
2 more practices, plus podcasts, books and research, live in Go deeper below.
03When to get help nowWhen this needs more than watchful waiting
Emergency red flags, same-week signs, and where to find a menopause-trained practitioner.
When this needs more than watchful waiting
6 more signs it needs a doctor this week
Sudden severe one-sided pelvic pain — go to the ER
Ovarian torsion can lose an ovary in hours. Sudden severe pain in one side of the pelvis, often with nausea/vomiting, especially with a known cyst, is an emergency — same day, not next week.
Any ovarian cyst after menopause
New ovarian cyst after 12+ months without a period always warrants proper assessment: transvaginal ultrasound with a risk score, CA-125, and a gynaecology opinion. Most are benign, but the workup is the point.
Persistent bloating, early satiety, urinary frequency for weeks
The classic ovarian-cancer symptom cluster is subtle: new persistent bloating, feeling full very quickly, needing to pee often, and pelvic/abdominal pain — for weeks, not days. Any woman over 40 with this cluster deserves a CA-125 and pelvic ultrasound, not an IBS label. This is one of the most missed diagnoses in women's health.
A cyst that keeps growing, or a complex/solid finding on scan
Growing, complex (mixed solid and cystic), or solid ovarian findings warrant gynaecology referral with a risk score. Not automatically surgery — but not just repeat scanning either.
Bleeding after menopause of any kind
Post-menopausal bleeding always needs urgent investigation (transvaginal ultrasound, biopsy where indicated) within weeks. Most causes are benign; endometrial cancer must be ruled out.
Family history of ovarian/breast cancer or BRCA/Lynch
A cyst on the ovary of someone with a known BRCA1/2, Lynch syndrome, or strong family history of ovarian, breast, endometrial or colorectal cancer is a different conversation — genetic-service-aware gynaecology, not routine follow-up. Say it in the appointment.
Go deeper
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Practices to try this week, voices worth hearing, books worth your bedside table, rooms where members are talking, the candid tips Nila would share over a cup of tea, and the research the editorial team is watching.
Where and when the pain is
Left, right, or both sides; constant, cyclical, or after activity/sex; how many days per cycle; whether it's 1–10 severe or a background ache. Note anything that reliably makes it worse (sex, exercise, bowel movements, particular movements).
Cycle context
Last period, cycle length recently, any late or missed cycles, any bleeding between periods, any post-menopausal bleeding (even spotting). This changes the differential completely.
Bloating, urinary and bowel symptoms
New persistent bloating, feeling full quickly, needing to pee more often, constipation. Individually these are usually nothing; persistent and combined they are on the ovarian-cancer symptom list and worth naming rather than dismissing.
Family history
Ovarian, breast, endometrial, colorectal cancer in first-degree relatives; known BRCA1/2 or Lynch syndrome in the family. This changes both the workup and any decision about surgery.
Previous scans and prior cysts
If you've had scans before, bring the dates and reports if you can. 'Same cyst, same size' vs 'new cyst, bigger' is a different conversation.