Most women develop ovarian cysts at some point, often without ever knowing it. Functional cysts, the most common type, form as part of the normal menstrual cycle and typically disappear on their own within a few months. The trickier cases involve cysts that grow, rupture, twist, or carry a risk of malignancy. Understanding which kind of cyst you have shapes everything that comes next, from watchful waiting to surgical removal. For related conditions, see our medical conditions guide.
What Ovarian Cysts Are
An ovarian cyst is a fluid-filled or solid sac that forms within or on the surface of an ovary. As MedlinePlus explains, these sacs often develop during ovulation and generally cause no health problems, resolving on their own in most cases. The American College of Obstetricians and Gynecologists (ACOG) distinguishes functional cysts (which arise from the normal menstrual cycle) from non-functional cysts (which can be benign tumors, endometriomas, or, less commonly, malignancies). Functional cysts are by far the most common, particularly in premenopausal women.
Most cysts are small (under 5 cm), asymptomatic, and resolve on their own within one to three menstrual cycles. The challenge is identifying the small subset that need imaging follow-up, surgical removal, or urgent care.
Types of Cysts
Functional cysts include follicular cysts (when a follicle does not release its egg and continues growing) and corpus luteum cysts (when the corpus luteum continues filling with fluid after ovulation). Both types usually resolve in about 6 to 12 weeks without treatment.
Non-functional cysts include dermoid cysts (mature cystic teratomas that can contain hair, skin, or even teeth), endometriomas (“chocolate cysts” caused by endometriosis), cystadenomas (benign tumors of the ovary’s epithelial surface), and the multiple small follicles seen in polycystic ovary syndrome (which are technically immature follicles rather than true cysts). Borderline ovarian tumors and ovarian cancers can also present as cystic masses.
Hemorrhagic cysts are functional cysts that have bled internally and are common, particularly with corpus luteum cysts. They typically resolve over 6 to 12 weeks but can be acutely painful, especially when they rupture.
Cyst Types at a Glance
| Type | What it is | Typical course |
|---|---|---|
| Follicular / corpus luteum (functional) | Formed by the normal menstrual cycle | Most common; usually resolve on their own |
| Hemorrhagic | A functional cyst that has bled internally | Usually resolves; can be painful |
| Dermoid (teratoma) | Contains tissue such as skin, hair, or fat | Benign; may need removal if large |
| Endometrioma | Linked to endometriosis | Does not resolve on its own; often treated |
| Cystadenoma | Benign epithelial tumor | May need surgical removal |
This table is a general overview, not a diagnosis. Only imaging and a clinician’s assessment can determine which type a specific cyst is.
Causes and Risk Factors
Functional cysts result from normal ovulatory function and are most common in women aged roughly 15 to 50. Hormonal contraception (combined pills) suppresses ovulation and reduces the formation of new functional cysts. Endometriomas are linked to endometriosis. Dermoid cysts and cystadenomas are sporadic and not strongly linked to specific risk factors.
Postmenopausal women generally do not form functional cysts, so any cyst found after menopause warrants closer attention. Genetic factors (BRCA1, BRCA2, Lynch syndrome) raise the risk of ovarian cancer and sometimes prompt earlier or more thorough workup of cysts. Pregnancy can produce theca lutein cysts. Polycystic ovary syndrome involves multiple small follicles but functions differently from a solitary cyst.
Symptoms
Most ovarian cysts cause no symptoms and are found incidentally on a pelvic exam, ultrasound, or imaging done for other reasons. When symptoms do occur, they can include pelvic pain (dull or sharp), pelvic pressure or fullness, bloating, painful intercourse, urinary frequency or urgency from compression, irregular menstrual cycles, and breast tenderness.
Acute, severe pain raises concern for two emergencies described below: cyst rupture and ovarian torsion. Both are time-sensitive and are covered in their own section because recognizing them quickly can protect your fertility and, rarely, your life.
Ovarian Torsion and Rupture: Know the Emergencies
Ovarian torsion occurs when the ovary twists on its blood supply. It causes sudden, severe pain on one side of the pelvis, often with nausea and vomiting, and sometimes lightheadedness or a rapid heartbeat. According to the Cleveland Clinic, torsion is a surgical emergency: if blood flow is not restored, the ovary can be lost. Larger cysts (greater than 5 cm), dermoid cysts, and cysts on a stalk carry a higher torsion risk.
Cyst rupture causes sudden sharp pain, often during physical activity or intercourse. Many ruptures settle with observation and pain control, but a rupture with significant internal bleeding can cause dizziness, faintness, a racing heart, or pallor and requires emergency evaluation. MedlinePlus specifically lists a cyst that ruptures or bleeds as a situation needing prompt medical attention.
When to seek emergency care: Call 911 or go to the nearest emergency room if you experience sudden, severe pelvic or abdominal pain (especially on one side, and especially with nausea or vomiting), or signs of internal bleeding such as dizziness, fainting, a rapid heartbeat, or severe pallor. Sudden severe one-sided pain with nausea suggests ovarian torsion, and torsion requires surgical intervention within hours to save the ovary. Do not wait to see whether the pain passes.
Diagnosis
Pelvic ultrasound is the imaging workhorse for ovarian cysts. Transvaginal ultrasound provides the best view of the ovary and the cyst’s internal characteristics. Simple cysts (uniformly fluid-filled, thin-walled, with no septations or solid components) carry minimal cancer risk. Complex cysts (with septations, solid components, papillary projections, or thick walls) require closer evaluation.
The IOTA simple rules and the ADNEX model are validated tools for stratifying cyst risk on ultrasound. CA-125 blood testing has limited usefulness in premenopausal women, because it can be elevated in many benign conditions including endometriosis, fibroids, pelvic infection, and pregnancy; it is more informative in postmenopausal women, but it is only one piece of the picture and a normal result does not rule out cancer. Cleveland Clinic emphasizes that a comprehensive evaluation weighs age, symptoms, ultrasound features, and risk factors together.
MRI is sometimes used to further characterize indeterminate masses. CT is generally reserved for staging if cancer is suspected. Persistent cysts that meet imaging criteria for possible malignancy are referred to gynecologic oncologists for surgical management.
Cancer Red Flags: When to Push for Evaluation
The vast majority of cysts are benign, but a handful of symptoms deserve prompt, non-emergency evaluation because they can occasionally signal ovarian cancer: persistent bloating, feeling full quickly or difficulty eating (early satiety), pelvic or abdominal pain, and urinary urgency or frequency that are new, persistent (lasting more than a few weeks), and occur most days. These symptoms are common and usually have benign causes, but their persistence is the reason to see a clinician rather than wait. The concern is higher in postmenopausal women and in those with a strong family history or a known BRCA or Lynch syndrome mutation. Any new cyst or pelvic pain after menopause always warrants evaluation.
Treatment Options
Most simple cysts are managed with watchful waiting, with a repeat ultrasound in about 6 to 12 weeks to confirm resolution. Combined hormonal contraception does not shrink an existing cyst but can prevent new functional cysts from forming, which is useful for women with recurrent symptomatic cysts. Any decision to start, stop, or change medication belongs with a prescriber; this guide intentionally gives no medication doses.
Surgery is considered for cysts that are persistent, large (often cited as roughly greater than 5 to 10 cm), growing, complex on imaging, persistently symptomatic, or found in postmenopausal women. Cystectomy (removing the cyst while preserving the ovary) is generally preferred in women of reproductive age. Oophorectomy (removing the entire ovary) is reserved for postmenopausal women, suspected malignancy, or when ovarian preservation is not feasible. Laparoscopic (minimally invasive) surgery is the standard approach for most benign cysts.
Acute torsion requires emergency surgery to untwist the ovary and remove the cyst; detorsion within roughly 6 to 8 hours often saves the ovary. A rupture without ongoing bleeding is typically managed with observation and pain control, while a rupture with significant internal bleeding requires surgery. Many women with recurrent painful cysts find that addressing related gynecologic conditions like endometriosis improves overall management.
Cysts in Postmenopausal Women
Cysts in postmenopausal women warrant closer scrutiny because the ovaries should not be producing functional cysts at this stage. Simple cysts smaller than 5 cm with a normal CA-125 can often be followed with serial ultrasound, but larger or complex cysts frequently require surgical evaluation. As Cleveland Clinic notes, cysts that develop after menopause are more likely to be cancerous than those that form before menopause, so the threshold for referral is lower.
Pregnancy and Ovarian Cysts
Cysts found during early pregnancy are usually corpus luteum cysts that resolve by the second trimester. Persistent pregnancy cysts may be observed, with surgery reserved for symptomatic, large, or suspicious lesions. The second trimester is generally the safest time for surgical intervention if it is needed. Decisions about hormonal contraception before or after pregnancy should be made with your clinician.
Prevention and Monitoring
You cannot fully prevent ovarian cysts. Combined hormonal contraception reduces the formation of new functional cysts by suppressing ovulation, which is useful in women with frequent symptomatic cysts. Maintaining regular gynecologic care allows incidental cysts to be identified and monitored appropriately.
For women with risk factors for ovarian cancer (BRCA mutations, strong family history), more intensive surveillance or risk-reducing surgery may be appropriate. That decision involves multiple factors and benefits from genetic counseling.
When to See a Doctor
Schedule an evaluation for new pelvic pain, persistent bloating, pressure on the bladder or bowel, irregular periods, or any pelvic mass found on exam or imaging. Postmenopausal pelvic pain or any new cyst always warrants evaluation. Recurrent cysts justify a discussion about whether hormonal suppression is right for you.
Frequently Asked Questions
Are ovarian cysts cancer?
The vast majority of ovarian cysts are benign. Functional cysts, dermoids, and most cystadenomas are not cancerous. The risk of malignancy depends on age, imaging features, and risk factors, and postmenopausal cysts carry a higher risk than premenopausal cysts.
Can ovarian cysts affect fertility?
Most do not. Endometriomas can reduce ovarian reserve over time. Functional cysts and small benign cysts generally do not affect fertility. Surgical removal of cysts can sometimes reduce ovarian reserve, particularly with bilateral surgery or repeated procedures. See our female infertility guide for more.
Do ovarian cysts go away on their own?
Most functional cysts resolve within one to three menstrual cycles without treatment. Non-functional cysts (dermoids, cystadenomas, endometriomas) typically do not resolve on their own and may require surgical removal if they are large, symptomatic, or growing.
Will birth control pills shrink an existing cyst?
No. Combined oral contraceptives prevent new functional cysts from forming but do not actively shrink an existing cyst. They are used to reduce recurrence in women with frequent functional cysts. Existing cysts resolve on their own timeline.
How do I know if a cyst has twisted or ruptured?
You cannot reliably tell on your own, which is why sudden, severe one-sided pelvic pain, especially with nausea, vomiting, faintness, or a rapid heartbeat, is a reason to seek emergency care rather than wait it out. A clinician with imaging can make the distinction quickly.
Quick summary: Most ovarian cysts are benign and resolve on their own, especially functional cysts in premenopausal women. Pelvic ultrasound guides monitoring, and management ranges from watchful waiting to hormonal therapy or surgery, all directed by a clinician. Two situations are emergencies: ovarian torsion (sudden severe one-sided pain with nausea or vomiting) and a rupture with heavy internal bleeding (severe pain with dizziness or faintness) – call 911 or go to the ER. This article is educational and is not a substitute for care from a qualified clinician, and it intentionally provides no medication doses.
The Practical Takeaway
Most ovarian cysts are benign, asymptomatic, and self-resolving. Watchful waiting with repeat imaging is appropriate for the great majority of premenopausal cysts. Postmenopausal cysts, large cysts, complex imaging features, and persistent symptoms shift management toward surgical evaluation. Sudden severe pain warrants urgent evaluation because torsion and significant rupture are time-sensitive emergencies. The whole conversation about ovarian cysts is largely about distinguishing the common, benign cases from the small subset that need closer attention, and a knowledgeable clinician with imaging in hand can usually make that distinction quickly. Use this guide to prepare questions for that visit rather than as a replacement for personalized medical advice.
Sources
- MedlinePlus (U.S. National Library of Medicine), Ovarian Cysts
- American College of Obstetricians and Gynecologists (ACOG), Ovarian Cysts (FAQ)
- Cleveland Clinic, Ovarian Cysts