An ovarian cyst is caused when fluid builds up on your ovary. The National Institutes of Health website states, ʺthis occurs when a follicle breaks open and does not release an egg (during ovulation).ʺ

An ovarian cyst can grow on the ovary or in the ovary. They can range in shape from the size of a plum to a grapefruit. Women generally develop ovarian cysts during their childbearing years. It is uncommon, but not impossible, for a woman to develop a cyst during menopause.

Most ovarian cysts are noncancerous.

There are several types of ovarian cysts. One type of cyst is called the corpus luteum cyst. The other and most common type of ovarian cyst is called a follicular cyst. The corpus luteum cyst contains a trace amount of blood and the follicular cyst contains fluid. If you do not ovulate, you cannot develop follicular cysts.

https://www.empowher.com/ovarian-cysts/content/what-ovarian-cyst