An ovarian cyst is a fluid-filled sac that forms on or inside an ovary. Females have two ovaries, and each ovary is about the size and shape of an almond. Eggs develop and mature in the ovaries, and they are released in monthly cycles during the childbearing years. Ovarian cysts are common, and most of the time, they are harmless and go away without treatment within a few months. However, sometimes ovarian cysts can become twisted or burst open, causing serious symptoms.

Most ovarian cysts form as a result of the menstrual cycle, and these are called functional cysts. There are two types of functional cysts: follicle cysts and corpus luteum cysts. Follicle cysts form when ovulation doesnt occur, and a follicle doesnt rupture or release its egg but instead grows until it becomes a cyst, or when a mature follicle involutes (collapses on itself) . Corpus luteum cysts form when the follicle releases its egg but then reseals and fills with fluid.

Other types of cysts are much less common, and some of them are related to endometriosis, a condition that causes cells similar to those that line the inside of the uterus to grow outside the uterus.

Most ovarian cysts cause no symptoms and go away on their own, but a large ovarian cyst can cause pain or discomfort. Symptoms of a large ovarian cyst may include pelvic pain, bloating, swelling, or a feeling of heaviness in the abdomen. If you experience any of these symptoms, it is important to see a doctor.

Diagnosis of ovarian cysts is usually done through an ultrasound, which is the primary tool used to document the cyst. Treatment options depend on the type and size of the cyst, as well as the age and overall health of the patient. Most cysts do not require treatment, but some may need to be removed surgically.