Ovarian cysts are fluid-filled sacs that develop on or inside an ovary. They're extremely common — most women will have at least one at some point in their lives — and the vast majority are harmless "functional" cysts that resolve on their own without treatment.
That said, some cysts do cause symptoms, and a small number need medical management. Understanding the difference helps you know when to simply monitor and when to call your doctor.
Types of Ovarian Cysts
Follicular cysts
The most common type. Develop when a follicle doesn't release its egg and fills with fluid. Usually resolve within 1–3 menstrual cycles with no treatment needed.
Corpus luteum cysts
Form from the follicle after ovulation. Can fill with blood or fluid and cause pain. Usually dissolve within a few weeks but can occasionally bleed.
Endometriomas
Caused by endometriosis — endometrial tissue grows on the ovary and fills with old blood ("chocolate cysts"). These require monitoring and sometimes surgery.
Dermoid cysts
Contain tissue like hair, skin, or teeth — they develop from embryonic cells. Usually benign but need surgical removal if large.
Cystadenomas
Develop from ovarian tissue and can grow large. May be filled with watery or mucous fluid and typically require surgery.
PCOS cysts
In PCOS, multiple small follicles that didn't release eggs remain on the ovary. These are not true cysts — they're follicles — and PCOS is managed differently from a single ovarian cyst.
Ovarian Cyst Symptoms
Many ovarian cysts cause no symptoms at all and are found incidentally during a pelvic ultrasound. When symptoms do occur, they can include:
- Dull aching or pressure in the lower abdomen, usually on one side
- Bloating or a feeling of fullness in the pelvis
- Pain during sex (particularly deep penetration)
- Changes to your menstrual cycle — heavier, lighter, or irregular periods
- Spotting between periods
- Pain during bowel movements or urination if the cyst is pressing on the bladder or rectum
- Nausea or vomiting
Sudden severe pelvic pain, pain with fever and vomiting, or pain with faintness/dizziness may indicate a ruptured cyst or ovarian torsion — both are medical emergencies. Don't wait — go to hospital immediately.
Diagnosis
Ovarian cysts are diagnosed primarily through pelvic ultrasound. Your doctor will assess the size, appearance (simple fluid-filled vs. complex with solid components), and location of the cyst. Blood tests including CA-125 (a tumour marker) may be ordered, though CA-125 can be elevated by many benign conditions including endometriosis and pregnancy.
Treatment Options
Most functional cysts don't need treatment:
- Watchful waiting — small, simple cysts in premenopausal women are usually monitored with a repeat ultrasound in 6–12 weeks to check for resolution
- Pain relief — over-the-counter pain medications (ibuprofen, paracetamol) for discomfort
- Hormonal contraception — the pill can prevent new functional cysts from forming, though it won't shrink existing ones
- Surgery — laparoscopic removal (cystectomy) for cysts that are large (>5–7cm), persistent, complex-looking, causing significant symptoms, or in postmenopausal women
Ovarian Cysts and Fertility
Most functional cysts don't affect fertility and often resolve before you start trying to conceive. Endometriomas and large cysts may impact fertility by affecting ovarian reserve or blocking the fallopian tubes. If you have a known cyst and are trying to conceive, discuss the timing and management with your doctor before starting.
Track Your Cycle, Know Your Body
Flow & Glow is a printable menstrual cycle tracker — log periods, symptoms, mood, cervical mucus, and cycle patterns month by month to spot trends and feel in control.