However, occasionally it swells with fluid or blood and remains on the surface of the ovary as a cyst. The most common abnormal cyst is a dermoid cyst. These cysts are similar to skin tissue on the outside and are filled with fatty material and sometimes bits of bone, hair, and cartilage. Ovarian cysts often cause no symptoms at all. If the cyst becomes twisted, it usually causes severe abdominal pain, nausea, and vomiting.
Ovarian cysts are sometimes difficult to diagnose.
It is not always clear whether the mass that the doctor feels during an exam is attached to the ovary or to some other organ, is stool in the rectum, or is merely a full bladder. Ultrasound is frequently helpful in confirming the diagnosis and measuring the size of the cyst. Abnormal cysts are usually 5 cm or larger. Functional ovarian cysts are common and seldom require any treatment. They may disappear in a few months without any treatment.