Ovarian cyst

Very common and usually harmless. Sudden severe one-sided pelvic pain is the exception and is an emergency.

What it is

A fluid-filled sac on an ovary. Most are functional cysts, part of the normal menstrual cycle, and they come and go without anybody knowing.

Most cause no symptoms and are found incidentally on a scan. Most resolve on their own within a few months.

Two situations matter.

**Ovarian torsion**, where a cyst causes the ovary to twist and cut off its own blood supply, causes sudden severe one-sided pain with vomiting and is a surgical emergency. Delay costs the ovary.

**Malignancy.** Most cysts are benign, and the risk rises after the menopause. Any cyst in a post-menopausal woman is assessed more carefully, usually with a CA125 blood test and a risk score. See ovarian cancer.

Cysts also occur in endometriosis, as endometriomas, and in polycystic ovary syndrome, which despite its name is a hormonal condition rather than a problem of cysts.

Management is usually watchful, with a repeat scan, rather than surgical. Removing ovaries unnecessarily has consequences including early menopause, so conservative management is the default for a reason.

Signs you might notice

Usually none.

Pelvic pain or a dull ache, sometimes one-sided.

Bloating, or a feeling of fullness or pressure.

Pain during sex.

Irregular periods, or heavier periods.

Needing to pass urine more often.

999 or A and E: sudden severe one-sided pelvic pain, especially with vomiting, faintness or a rapid pulse. That may be torsion or a ruptured cyst with bleeding.

Urgent: pain with fever; pain with a positive pregnancy test, which may be an ectopic pregnancy; or persistent bloating, feeling full quickly and abdominal pain on most days for three weeks, which needs assessment for ovarian cancer.

How it can affect day-to-day life

Being told there is a cyst is frightening, and the word is often heard as a step towards cancer when for most women it is not. Clear explanation of the plan, and of why watching is appropriate, prevents months of anxiety.

Waiting for a repeat scan is its own ordeal and the reasoning should be explained rather than implied.

The persistent-symptoms pattern, bloating and early fullness on most days, is the one that matters and is easily lost among reassurances about a benign cyst.

Torsion is often diagnosed late because severe pelvic pain in a young woman gets attributed to period pain or to a urinary infection. Sudden, severe, one-sided and with vomiting is different.

For anyone with a learning disability or communication difference, sudden distress with abdominal guarding deserves examination rather than explanation.

Supporting someone well

Get sudden severe one-sided pelvic pain assessed as an emergency, particularly with vomiting.

Ask what type of cyst and what the follow-up plan is, and put the repeat scan date in a diary.

Ask about CA125 and a risk score if post-menopausal.

Track persistent symptoms: bloating, early fullness, pelvic pain, urinary frequency on most days for three weeks, and take that record to the GP.

Ask about ovary-preserving surgery rather than removal where surgery is needed.

Do a pregnancy test with any new pelvic pain of reproductive age.

Ask about pain management rather than living with it while waiting.

Where to get help

A GP practice for assessment and ultrasound.

A and E for sudden severe pelvic pain, faintness, or pain with a positive pregnancy test.

Gynaecology for persistent or complex cysts.

Target Ovarian Cancer and Eve Appeal for symptom information and support.