What Causes Cysts and When to Worry

5. Ovarian Cysts

Ovarian cysts are common in menstruating individuals, and often occur during ovulation. There are two main types of ovarian cysts. In a typical menstruation cycle, the ovary releases an egg every month.

The egg grows in a sac inside the ovary called a follicle. The follicle breaks open when the egg matures, releasing it. A follicle cyst can form when the follicle does not release the egg and, instead, it keeps growing, forming a cyst.

These cysts typically have no symptoms and go away on their own within three months.

When the follicle does release the egg, the empty sac collapses into a mass of cells called the corpus luteum, which makes hormones in preparation for the next menstrual cycle.

If the sac does not shrink, it will reseal itself after releasing the egg, trapping fluid inside, and forming a corpus luteum cyst.

These cysts usually go away after a few weeks, but they can grow up to four inches wide and cause pain or bleeding or twist the ovary.