What are ovarian cysts?
The ovaries are small glands on each side of the uterus that make eggs and hormones. An ovarian cyst is a fluid-filled sac that forms on or inside an ovary. Many ovarian cysts develop as part of the normal menstrual cycle. These are called functional cysts, and they’re common during the childbearing years. Most ovarian cysts are harmless, not related to cancer, and go away on their own within a few months. Cysts found after menopause are more likely to need closer evaluation.
At Penn Medicine, our women’s health team provides expert diagnosis and tailored care for both simple and complex cysts. We take a team-based approach, bringing together specialists in gynecology, radiology, fertility, and, when needed, gynecologic oncology. Whether you need monitoring, help managing pelvic pain, or surgical care, we guide you through your options clearly and compassionately.
When ovarian cysts cause symptoms
Many ovarian cysts are small and don’t cause any symptoms. You may not know you have one unless it’s found during a pelvic exam or imaging test. When symptoms do appear, they can range from mild discomfort to sudden and severe pain.
Mild pelvic pain and bloating are common. You may also notice:
- Lower abdominal pain
- A dull ache in the lower back
- A feeling of fullness on one side
- Pain during sex or certain movements
- Pain with bowel movements or urination
Sometimes symptoms signal a more serious problem, like a cyst that has grown very large, ruptured, or caused the ovary to twist. This twisting is called ovarian torsion.
If you have sudden, sharp pelvic pain along with any of the following, seek medical care right away:
- Nausea or vomiting
- Dizziness, weakness, or feeling faint
- Fever
Understanding the types of ovarian cysts
Not all ovarian cysts are alike. Most are harmless and part of your regular menstrual cycle. Others may need closer monitoring. Knowing which type you have helps guide decisions about your care.
Simple cysts, also called functional cysts, are the most common type. They are fluid-filled and usually form during ovulation. Most go away on their own within a few menstrual cycles. Functional cysts are not cancer.
Types include:
- Follicular cyst: Forms when a follicle doesn’t release its egg and continues to grow.
- Corpus luteum cyst: Develops after an egg is released. It may fill with fluid or blood and sometimes cause pain.
- Hemorrhagic ovarian cyst: A cyst that contains blood. If it ruptures, it can cause sudden pain and internal bleeding.
Complex cysts are less common. They may contain solid areas or other features that require closer evaluation. Most are still benign, but complex cysts found after menopause have a higher risk of cancer.
Certain complex cysts, like dermoid cysts and cystadenomas, can grow large. Large cysts may increase the risk of complications. These can include a ruptured ovarian cyst or ovarian torsion, which require urgent medical care.
What causes ovarian cysts?
The most common cause of ovarian cysts is ovulation. These functional cysts form as part of your menstrual cycle. Each month, a small sac called a follicle grows on your ovary. The follicle holds a developing egg and makes hormones. When the egg is released, the follicle usually shrinks. If it doesn’t release the egg or shrink as expected, fluid can build up and form a cyst.
Other causes include:
- Hormone-related conditions like polycystic ovary syndrome (PCOS)
- Endometriosis
- Abnormal cell growth, which can lead to dermoid cysts or cystadenomas
- Severe pelvic infections like pelvic inflammatory disease (PID)
- Fertility medications, which may cause multiple cysts to form
Diagnosing ovarian cysts
Your provider might find a cyst during a routine pelvic exam or during imaging done for something else. If a cyst is suspected, additional testing can help confirm the diagnosis and guide next steps.
Blood tests may be used to check hormone levels. A CA-125 test may be ordered in certain situations, especially after menopause or if imaging results are unclear. A pregnancy test may also be done. Imaging tests help determine the cyst’s size, type, and features.
Treatment options for ovarian cysts
Often, the best approach is watchful waiting. Because most functional ovarian cysts go away within eight to 12 weeks, your provider may repeat an ultrasound to confirm it has resolved. Pain relief medication may be recommended to ease discomfort. If you frequently develop cysts, birth control pills may be suggested. While they don’t shrink an existing cyst, they can prevent ovulation and reduce the chance of new cysts forming.
Surgery may be recommended if a cyst is very large, continues to grow, causes significant pain, or raises concern for cancer. Surgical options include minimally invasive techniques or, in more complex cases, laparotomy.
In rare cases, a cyst can be a sign of ovarian cancer. If cancer is suspected, you’ll be referred to our specialists in gynecologic cancer care. Penn Medicine is a leader in cancer care, offering advanced treatment options and coordinated support.