Most ovarian cysts are small, harmless, and never cause a single symptom. But when a cyst grows large enough, produces hormones, or develops complications, it can affect everything from daily comfort to fertility. The problems a cyst causes depend largely on its type, size, and whether it ruptures or twists.
Pelvic Pain and Pressure
The most recognizable symptom of an ovarian cyst is pain or pressure in the lower abdomen, typically on the side where the cyst sits. This can range from a dull, heavy ache to sharp, intermittent pain that comes and goes. Some women also feel a dull ache radiating into the lower back and thighs. Pain during sex is another common complaint, especially with deeper penetration that shifts the ovary.
Bloating and a feeling of abdominal fullness often accompany larger cysts. You may notice your lower belly looks swollen or feels tight, even without changes in diet or weight. Unexplained weight gain can sometimes be traced back to a large cyst or the fluid retention it triggers.
Bladder and Bowel Problems
A cyst doesn’t have to be enormous to press on nearby organs, but size matters. When a cyst grows large enough to push against the bladder, you may feel the need to urinate more frequently or have trouble fully emptying your bladder. If it presses on the bowel instead, you might struggle to have complete bowel movements or feel persistent lower abdominal pressure that mimics digestive issues. These symptoms are often mild and easy to dismiss, which is part of why cysts sometimes go unnoticed for months.
Menstrual Cycle Disruptions
Functional cysts, the most common type, form directly from the ovulation process. Normally, an egg grows inside a small fluid-filled sac called a follicle, which bursts to release the egg and then shrinks. When that process stalls, the follicle can swell into a cyst. Because these cysts arise from the same hormonal machinery that drives your cycle, they can throw off its timing.
You might notice periods that are heavier than usual, irregular spotting between periods, or cycles that arrive late. Polycystic ovary syndrome (PCOS), a condition where many small cysts form on the ovaries due to altered hormone levels, is a well-known cause of missed or infrequent periods. The small follicles in PCOS never mature to the point of ovulation, which disrupts the hormonal signals that regulate bleeding. Unusual vaginal bleeding and increased breast tenderness are also reported, though less commonly.
Ruptured Cysts
A cyst can rupture on its own, and when it does, the experience is hard to miss. The hallmark is sudden, sharp pain in the lower abdomen or back, sometimes accompanied by vaginal spotting or bloating. For many women, a ruptured cyst is painful but resolves without treatment as the fluid is reabsorbed by the body.
The risk rises when the cyst is an endometrioma (a cyst filled with old blood from endometriosis tissue) or when blood vessels tear during the rupture. Internal bleeding from a ruptured cyst can cause faintness, dizziness, and rapid heartbeat. If the cyst was infected before it burst, bacteria can spread into the abdominal cavity and, in rare cases, trigger sepsis. Heavy vaginal bleeding, fever, or severe nausea and vomiting alongside abdominal pain are all signs that a rupture needs emergency attention.
Ovarian Torsion
This is the complication doctors worry about most. Ovarian torsion happens when a cyst makes the ovary heavy or enlarged enough that it twists on the ligaments and blood vessels that support it. That twist cuts off blood flow. Without blood supply, ovarian tissue starts to die within hours.
The pain from torsion is usually severe and sudden, often on one side, and frequently comes with nausea, vomiting, or diarrhea. The challenge is that these symptoms overlap with many other conditions, from appendicitis to kidney stones, so torsion requires a high level of suspicion. Ultrasound with blood flow imaging can suggest the diagnosis by showing an enlarged ovary with reduced or absent circulation, but the definitive answer comes during surgery. Torsion is a surgical emergency because saving the ovary depends on restoring blood flow quickly.
Effects on Fertility
Simple functional cysts rarely threaten your ability to conceive. They form as part of normal ovulation and usually dissolve within a few menstrual cycles. In many cases, having a functional cyst actually confirms that ovulation is occurring.
Endometriomas are a different story. These cysts grow from endometriosis tissue on or inside the ovary, and their presence is linked to reduced ovarian reserve, meaning both the number and quality of eggs can decline. This negative impact on fertility exists whether or not the cyst is surgically removed, though treatment decisions depend on factors like the cyst’s size and a woman’s reproductive plans. PCOS-related cysts also affect fertility, primarily by preventing ovulation altogether, though this is often manageable with medical support.
Cancer Risk
The fear that a cyst could be cancerous is common, but the actual risk is low. In premenopausal women, the chance that a symptomatic ovarian cyst is malignant is roughly 1 in 1,000. That risk increases modestly with age, reaching about 3 in 1,000 by age 50. Postmenopausal women face higher odds overall because the ovaries are no longer producing functional cysts, so any new growth warrants closer evaluation.
Doctors use ultrasound characteristics, blood markers, and age to assess whether a cyst looks suspicious. Solid components inside a cyst, irregular borders, and blood flow within the mass all raise concern. Most cysts that appear simple and fluid-filled on imaging are benign and can be monitored rather than removed.
Fluid Buildup in the Abdomen and Chest
In rare cases, a benign ovarian tumor (typically a solid type called a fibroma) can trigger a condition known as Meigs syndrome: fluid accumulates in both the abdomen and the chest cavity. The tumor appears to irritate the lining of the abdominal cavity or secrete fluid directly, particularly when it exceeds 10 centimeters in diameter. That abdominal fluid then migrates upward through tiny lymphatic channels in the diaphragm, causing a pleural effusion around the lungs.
The result can be shortness of breath, abdominal swelling, and a clinical picture that initially looks alarming. The reassuring part is that removing the tumor resolves both the abdominal and chest fluid completely, with no recurrence. Similar fluid collections can occur with other benign ovarian growths, a pattern sometimes called pseudo-Meigs syndrome.