Most ovarian cysts cause no symptoms at all and disappear on their own within two to three menstrual cycles. They’re extremely common, and the majority are “functional” cysts, meaning they form as a normal part of ovulation. But depending on the type, size, and behavior of a cyst, the experience can range from completely unnoticed to a medical emergency requiring surgery.
Most Cysts Are Harmless and Resolve Alone
The most common ovarian cysts are functional cysts. These form when a follicle either doesn’t release its egg or doesn’t shrink after releasing one. They’re small, fluid-filled, and a sign that your reproductive system is working as expected. They typically resolve without treatment in a few months.
Other types are less common but more persistent. Dermoid cysts contain tissue like skin, hair, or even teeth, formed from cells present since birth. Cystadenomas grow from the outer surface of the ovary and can fill with watery or mucous-like fluid. Endometriomas develop when tissue similar to the uterine lining grows on or inside the ovary. These types don’t go away on their own and may need monitoring or removal.
What Symptoms Feel Like
Small cysts rarely produce noticeable symptoms. When a cyst grows large enough to press on surrounding tissue, the most common sensation is pelvic pain, either a dull ache or a sharp pain on one side of your lower abdomen. Some people also feel fullness, pressure, or heaviness in the belly, similar to bloating that doesn’t go away after eating.
You might also notice changes in your menstrual cycle, pain during sex, or a frequent need to urinate if the cyst is pressing on your bladder. These symptoms overlap with many other conditions, which is why cysts are often discovered incidentally during an ultrasound done for another reason.
Two Emergencies to Recognize
Ovarian cysts can cause two serious complications that require immediate medical attention: rupture and torsion.
A ruptured cyst happens when the cyst wall breaks open, releasing fluid (and sometimes blood) into the pelvic cavity. This typically causes sudden, severe pain on one side of the pelvis. Some ruptures resolve on their own with rest and pain management, while others cause enough internal bleeding to need emergency treatment.
Torsion occurs when a cyst, especially a larger one, causes the ovary to twist on its own blood supply. Dermoid cysts and cystadenomas are particularly risky for this because they can grow large enough to shift the ovary out of position. The risk of torsion increases significantly once a cyst reaches 5 to 6 centimeters. Torsion causes intense, sudden pain often accompanied by nausea and vomiting. It’s a surgical emergency because a twisted ovary can lose blood flow permanently if not corrected quickly.
How Cysts Are Diagnosed
Transvaginal ultrasound is the standard first step. The probe sits close enough to the ovaries to produce detailed images showing the cyst’s size, shape, and internal structure. Your provider will look at whether the cyst is purely fluid-filled or contains solid components, whether it has thin or thick walls, and whether there are internal divisions called septations.
A simple, fluid-filled cyst with thin, smooth walls and no solid areas is almost always benign, regardless of your age. Features that raise concern include a cyst larger than 10 centimeters, solid components or irregular walls, thick internal divisions, and increased blood flow visible on Doppler imaging. These findings don’t automatically mean cancer, but they prompt further evaluation.
Blood tests measuring a protein called CA-125 are sometimes ordered, but they have significant limitations. Many non-cancerous conditions can raise CA-125 levels, and some ovarian cancers don’t produce elevated levels at all, especially in early stages. CA-125 is most useful as one piece of a larger picture rather than a standalone screening tool.
The “Watch and Wait” Approach
If your cyst is small, fluid-filled, and not causing symptoms, your provider will likely recommend watchful waiting. This means periodic follow-up ultrasounds, typically over a few months, to track whether the cyst changes in size or appearance. Many cysts shrink and vanish during this window without any intervention. This approach applies across age groups as long as the cyst looks benign on imaging.
When Surgery Becomes Necessary
Surgery is considered when a cyst is large, growing, causing persistent symptoms, or has concerning features on ultrasound. Cysts smaller than about 10 centimeters are generally removed through minimally invasive laparoscopic surgery, which involves small incisions, shorter recovery time, and less post-operative pain. Cysts larger than 12 centimeters are more likely to require an open procedure called a laparotomy, simply because there’s not enough room to safely extract them through a small incision.
The goal of surgery is usually to remove the cyst while preserving the ovary, especially in people who want to maintain fertility. In some cases, particularly when there’s concern about malignancy or when cysts recur repeatedly, removing the entire ovary may be recommended.
Effects on Fertility
Functional cysts do not affect your ability to get pregnant. In fact, developing them is a sign that ovulation is happening normally.
Two types of cysts can interfere with fertility. Endometriomas, linked to endometriosis, are associated with difficulty conceiving, likely because the surrounding inflammation damages egg quality and disrupts the ovarian environment. Polycystic ovary syndrome (PCOS) involves many small follicles on the ovaries along with hormonal imbalances, particularly elevated levels of male hormones and insulin. PCOS can reduce the frequency of ovulation, which directly affects the chances of conception.
Dermoid cysts and cystadenomas, despite sometimes requiring surgical removal, are not linked to infertility.
PCOS Is Not the Same as Having a Cyst
The naming is confusing, but PCOS and an isolated ovarian cyst are fundamentally different conditions. PCOS is a metabolic disorder affecting roughly 1 in 10 women. It involves a hormonal imbalance, including high insulin levels and elevated male hormones, that disrupts ovulation. The “cysts” visible on ultrasound in PCOS are actually underdeveloped follicles, not true cysts. PCOS is a chronic condition managed over time with lifestyle changes and sometimes medication.
An isolated ovarian cyst, by contrast, is usually a one-time structural event. It forms, may or may not cause symptoms, and either resolves or is removed. It doesn’t typically involve the widespread hormonal disruption that defines PCOS.