Ovarian cysts are common, and most are normal, harmless, and temporary. They happen when a fluid-filled sac forms on or inside an ovary, usually during the normal process of ovulation. The vast majority cause no symptoms and go away on their own within a few weeks or months. Only a small percentage of cysts are problematic, and even fewer are cancerous, especially in women of reproductive age.
What Exactly Is an Ovarian Cyst?
An ovarian cyst is a sac of fluid that develops on or inside an ovary. The ovary is about the size of a walnut and sits on either side of the uterus. Each month during a normal menstrual cycle, the ovary releases an egg. That process involves the growth of small structures called follicles.
Most cysts form from these follicles. When a follicle grows but does not release an egg, it can keep filling with fluid and become a cyst. This is called a functional cyst. It is the most common type and is directly tied to the menstrual cycle. Functional cysts are almost always benign and tend to dissolve on their own.
Other types of cysts exist too. Endometriomas form when tissue similar to the uterine lining grows on the ovary. Dermoid cysts contain tissue like hair, skin, or teeth because they develop from embryonic cells. Cystadenomas grow from cells on the outer surface of the ovary. These types are less common and may require different management.
Are Ovarian Cysts Normal During the Menstrual Cycle?
Yes. The menstrual cycle naturally produces small cysts every month. Before ovulation, a follicle grows to about 2 to 3 centimeters to prepare for egg release. This is technically a cyst, and it is a normal part of reproductive function.
After the egg is released, the follicle transforms into something called the corpus luteum. This structure produces hormones to support a possible pregnancy. Sometimes the corpus luteum fills with fluid and becomes a cyst. This too is a normal variation.
Most women develop at least one functional cyst at some point in their lives. Many never know they have one because it causes no symptoms and disappears silently. Routine ultrasounds often catch cysts that the woman had no idea were there.
What Symptoms Can Ovarian Cysts Cause?
Most cysts cause no symptoms at all. When symptoms do occur, they tend to be mild and relate to the size or location of the cyst. Common complaints include a dull ache in the lower abdomen or pelvis, a feeling of fullness or pressure, and mild pain during sex.
Some women notice pain around the time of ovulation or just before their period. This is often due to a cyst stretching the ovary or irritating nearby tissue. Bloating and changes in bowel habits can also occur, though these symptoms are nonspecific and can have many causes.
Severe symptoms are less common but require prompt medical attention. Sudden, sharp pelvic pain can signal a ruptured cyst or ovarian torsion, where the ovary twists on its blood supply. Fever, dizziness, fainting, or pain accompanied by nausea and vomiting also warrant urgent evaluation.
When Should You Worry About an Ovarian Cyst?
Most cysts are not dangerous, but some situations need closer attention. Size matters. A cyst larger than about 5 centimeters is more likely to cause symptoms or complications. Cysts larger than 7 to 10 centimeters carry a higher risk of rupture or torsion.
Appearance on ultrasound matters too. Simple cysts have thin walls and clear fluid inside. These are almost always benign. Complex cysts have irregular walls, solid areas, or internal debris. These need more evaluation because they may require surgery to rule out cancer.
Age is a significant factor. Ovarian cancer is rare in premenopausal women. The risk increases after menopause. A postmenopausal woman with a new ovarian cyst has a higher chance of malignancy than a younger woman with the same finding. Even so, most cysts in postmenopausal women are still benign.
How Are Ovarian Cysts Diagnosed?
Many cysts are found incidentally during a pelvic exam or ultrasound done for another reason. A pelvic exam can feel a mass, but it cannot determine what type of cyst it is. Ultrasound is the standard imaging tool because it shows the cyst’s size, shape, and internal structure clearly.
A transvaginal ultrasound provides the best view of the ovaries. A small probe is placed inside the vagina, allowing close imaging of the pelvic organs. This test can usually tell whether a cyst is simple or complex, which guides next steps.
Blood tests may be used in certain situations. The CA-125 test measures a protein that can be elevated in ovarian cancer. However, this test is not a reliable screening tool. Many benign conditions, including endometriosis, fibroids, and even normal menstruation, can raise CA-125 levels. Doctors typically order it only when ultrasound findings or other factors raise concern.
What Are the Treatment Options for Ovarian Cysts?
Treatment depends on the cyst’s characteristics and the woman’s age and symptoms. For a small, simple cyst in a premenopausal woman with no symptoms, the standard approach is watchful waiting. The doctor will repeat the ultrasound in 6 to 8 weeks to confirm the cyst has resolved. Most functional cysts do disappear in this timeframe.
Hormonal birth control is sometimes prescribed to prevent new cysts from forming. The pill stops ovulation, which prevents functional cysts from developing. However, birth control does not shrink an existing cyst. Some research suggests it does not speed up resolution either. It may still be recommended to regulate cycles and reduce the formation of future cysts.
Surgery is considered when a cyst is large, persists, causes significant pain, or looks suspicious on imaging. The two main surgical approaches are cystectomy, which removes only the cyst, and oophorectomy, which removes the entire ovary. Whenever possible, surgeons prefer cystectomy to preserve ovarian tissue. Many surgeries can be done laparoscopically through small incisions, which means faster recovery.
Can Ovarian Cysts Affect Fertility?
Most cysts do not affect fertility. Functional cysts arise from the normal ovulatory process and do not interfere with conception. They often resolve on their own without any treatment.
Some conditions that cause cysts can affect fertility. Endometriosis, which causes endometriomas, can damage the ovaries or fallopian tubes and reduce egg quality. Polycystic ovary syndrome involves many small follicles on the ovaries and is a leading cause of ovulatory infertility. In these cases, the underlying condition matters more than the cysts themselves.
Surgery for cysts can impact fertility in some cases. Removing a large cyst may remove healthy ovarian tissue along with it. This is why doctors try to preserve as much ovarian tissue as possible. Most women who have cyst removal surgery retain normal fertility afterward.
Are Ovarian Cysts Ever an Emergency?
Yes, though emergencies are uncommon. A ruptured cyst can cause sudden, severe pain and internal bleeding. Most ruptures are harmless and the pain resolves on its own. But a rupture that damages a blood vessel can cause significant blood loss and require emergency surgery.
Ovarian torsion is another emergency. The ovary twists around the ligaments that hold it in place, cutting off its blood supply. This causes sudden, severe pain that comes and goes. Torsion requires urgent surgery to untwist the ovary and restore blood flow. If treatment is delayed, the ovary can die and need removal.
Seek immediate medical care if you have sudden, severe pelvic pain, pain with fever, dizziness, or fainting. These symptoms could indicate rupture, torsion, or another serious condition. Do not wait to see if it passes.
Can Ovarian Cysts Be Prevented?
No method fully prevents ovarian cysts. Because functional cysts are a byproduct of normal ovulation, avoiding them would require stopping ovulation entirely. Hormonal birth control is the only reliable way to do this, and it does reduce the risk of functional cysts.
Other types of cysts, like endometriomas and dermoid cysts, are not preventable. They develop from tissue behavior rather than the menstrual cycle. Regular gynecologic exams can catch cysts early, but they cannot stop them from forming.
Knowing your body and tracking symptoms is the most practical approach. If you notice persistent pelvic pain, pressure, or changes in your cycle, mention it to your doctor. Most cysts will never need treatment, but the ones that do are best caught early.
Frequently Asked Questions
Can ovarian cysts go away on their own?
Yes, most functional cysts dissolve on their own within a few weeks to a few months. Simple cysts in premenopausal women are typically monitored with a follow-up ultrasound rather than treated.
What size ovarian cyst requires surgery?
Cysts larger than 5 centimeters are more likely to cause symptoms, and those larger than 7 to 10 centimeters carry higher risks of rupture or torsion. Surgery is recommended based on size combined with symptoms, ultrasound appearance, and the woman’s age.
Can ovarian cysts be cancerous?
Yes, but it is rare, especially in premenopausal women. The risk increases after menopause, and complex cysts on ultrasound require further evaluation to rule out malignancy.
Do ovarian cysts cause weight gain?
Large cysts can cause abdominal bloating or a feeling of fullness, but they do not cause true weight gain. Most cysts are too small to produce any noticeable change in the abdomen.
