Ovarian Cyst Symptoms — and What a Scan Can Tell You
Most ovarian cysts cause nothing at all. Here is what they do cause when they do, which symptoms are genuinely urgent, and how a scan separates the ordinary from the concerning.
Ovarian cysts are fluid-filled sacs that develop on or within an ovary, and they are extremely common. Most cause no symptoms whatsoever, form and resolve on their own across a menstrual cycle, and are found only incidentally on a scan arranged for something else. The majority are entirely benign.
That said, cysts can cause symptoms — and some of those symptoms are surprisingly indirect, which is why people often do not connect them to an ovary at all. A few require urgent care.
Sudden, severe one-sided pelvic pain — especially with nausea or vomiting, feeling faint, or a rapid pulse. This can indicate ovarian torsion (the ovary twisting on its blood supply) or a ruptured cyst with internal bleeding. Torsion is a surgical emergency and the ovary can be saved if treated quickly, so do not wait for a scan appointment. Fever with pelvic pain also needs same-day assessment.
What ovarian cysts actually feel like
When a cyst does cause symptoms, the usual pattern is:
- Pelvic pain on one side — a dull ache or heaviness, sometimes sharper, often coming and going
- Bloating or a feeling of fullness in the lower abdomen
- Pain during sex, particularly felt deep on one side
- Changes to your periods — heavier, lighter, or irregular
- Pain around ovulation or just before a period
Pain that comes and goes is characteristic, because functional cysts grow and resolve with the cycle. Persistent, unchanging symptoms are more likely to warrant investigation.
Can a cyst cause bladder or bowel symptoms?
Yes — and this catches people out, because the symptoms seem to belong to entirely different organs. The ovaries sit close to both the bladder and the bowel, so a cyst of any size can press on either.
Bladder symptoms. Pressure on the bladder reduces the volume it can comfortably hold, causing frequency, urgency, a sense of incomplete emptying, and occasionally leakage. It can feel very like a urinary infection — the distinguishing feature is that a cyst causes pressure without the burning, and urine tests come back clear. A cyst does not cause a urinary infection, though incomplete emptying from pressure can make infections more likely.
Bowel symptoms. Pressure backwards on the bowel can cause constipation, a sense of incomplete emptying, or discomfort on opening the bowels. Changes in bowel habit have many causes and should not simply be attributed to a known cyst without assessment.
Can you feel a cyst from the outside? Usually not. Small and moderate cysts are impalpable through the abdominal wall. A large cyst may be felt as a firm swelling low in the abdomen, and very large ones can visibly distend it — but the absence of anything you can feel says nothing about whether a cyst is present.
Types, and how a scan tells them apart
| Type | What it is | What usually happens |
|---|---|---|
| Follicular / corpus luteum | Functional cysts — part of the normal cycle | Resolve by themselves, commonly within two or three cycles |
| Haemorrhagic | A functional cyst that has bled internally | Typically settles on its own; can cause a sudden painful episode |
| Endometrioma | A cyst of endometriosis, with characteristic appearances | Usually monitored, and managed with your gynaecologist |
| Dermoid | Contains tissue such as fat and hair — benign | Does not resolve; monitored or removed depending on size and symptoms |
| Cystadenoma | A benign growth arising from ovarian surface cells | Can grow large; often removed |
Do not confuse a cyst with a follicle. Small fluid-filled follicles are a normal, healthy feature of ovaries in the reproductive years — eggs maturing, not a problem — and our guide to follicles versus cysts explains where the line is drawn. Similarly, a “polycystic appearance” describes a pattern of many small follicles, which becomes PCOS only alongside clinical criteria.
Could it be cancer?
This is the question underneath most searches about cysts, so here it is answered directly. The overwhelming majority of ovarian cysts are benign — particularly before the menopause, where functional cysts are part of normal physiology. Risk rises with age, and a new cyst after the menopause is assessed more carefully because functional cysts should no longer be forming.
Ultrasound is good at this distinction, because reassuring and concerning features look different. A simple cyst — thin-walled, entirely fluid, no solid parts, no internal blood flow — is reassuring at any age. Features that prompt further assessment include solid areas within the cyst, thick or irregular internal walls, blood flow inside solid components, fluid elsewhere in the abdomen, or substantial size. Those findings lead to gynaecology referral, not to a diagnosis on the spot — imaging describes, it does not diagnose.
You may also be offered a CA-125 blood test. It is genuinely useful in the right context and genuinely unreliable outside it — it can be raised by endometriosis, fibroids, infection, and even menstruation, and can be normal in early ovarian cancer. Our guide to a raised CA-125 explains why the scan and the blood test are read together rather than separately.
Does the size matter?
Less than people expect, and less than the character of the cyst. A 4cm simple cyst in a premenopausal woman is an ordinary finding that will very often have gone by the next scan. A much smaller cyst with solid components is the one that gets attention. Character first, size second — that is how these are assessed.
Size does matter for two practical reasons: larger cysts are more likely to cause pressure symptoms, and they carry a greater risk of torsion or rupture. That is why a large cyst may be removed even when it is clearly benign.
Follow-up usually means a repeat scan after an interval — commonly six to twelve weeks for a probable functional cyst, to confirm it has resolved. Where a cyst persists, grows, or has concerning features, referral to a gynaecologist follows. Our guide to pelvic reports decodes the wording you will see.
Your questions answered
What are the symptoms of an ovarian cyst?
Can an ovarian cyst cause constipation or bowel problems?
Can an ovarian cyst cause bladder problems or incontinence?
Can you feel an ovarian cyst from the outside?
Is a 4cm ovarian cyst something to worry about?
How do I know if an ovarian cyst is cancerous?
Do ovarian cysts go away on their own?
When should I go to A&E?
Where to go from here
Why normal follicles are often mistaken for something worrying.
Read the guide →
CA-125A Raised CA-125Why the blood test needs a scan alongside it to mean anything.
Read the guide →
£159Pelvic Ultrasound ScanThe examination that characterises and measures a cyst.
About the scan →
A cyst characterised, not just counted
Transabdominal and transvaginal scanning by HCPC-registered sonographers, cysts measured and characterised, findings explained on screen, and a written report usually within two hours for your GP.
Kensington, London W8 4ED
3 mins from Notting Hill Gate
This article is general information, not individual medical advice. Sudden severe pelvic pain needs emergency assessment. Ovarian cyst findings should be interpreted alongside your age, symptoms and menopausal status by your GP or gynaecologist; imaging describes appearances but does not provide a tissue diagnosis.
Written and clinically reviewed by the HCPC-registered sonographers who perform this scan at IUS London — a CQC-registered diagnostic ultrasound clinic (Provider ID 1-2775844974). Your own findings are explained to you at the scan and set out in your report.
Author: Yianni Kiromitis, Senior Sonographer, HCPC RA38415
Medically reviewed: 1 August 2026
