An ovarian cyst is a sac filled with liquid or semi-liquid material arising in an ovary. Ovarian cysts are usually diagnosed by chance as most simple ovarian cysts do not produce symptoms unless they have associated complications. Often they are discovered either during a regular pelvic examination or as an unexpected finding during an ultrasound examination of the pelvis.
Functional (normal) ovarian cysts are the most common type of ovarian cyst. They usually disappear by themselves and seldom require treatment. Cysts that become abnormally large or last longer than a few months should be removed or examined to determine if they are in fact something more harmful.