What Causes Ovarian Cysts?

The most common type of ovarian cyst, called a functional cyst, is formed during ovulation when either the egg isn't released or the follicle, or sac, doesn't dissolve after the egg is released. Cysts, or fluid-filled sacs that form in the ovaries, are very common in women of child-bearing age, according to WebMD. Other cysts develop from unopened follicles or from cells on the surface of the ovary.

Most ovarian cysts are painless. If a cyst becomes twisted, bleeds or ruptures, however, it can cause problems. Some symptoms of ovarian cysts mimic those of ovarian cancer, according to WebMD. Symptoms of both ovarian cysts and tumors include abdominal pain or bloating, difficult or frequent urination, dull ache in the lower back, pain during intercourse, painful or unusually heavy periods, unexplained weight gain, nausea, vomiting, loss of appetite or a quick feeling of fullness during or after eating.

Ovarian cysts and tumors are diagnosed with ultrasound or other imaging tests such as CT, MRI or PET scans, according to WebMD. Cysts and tumors can also be confirmed by measuring hormone levels, laparoscopic surgery or blood tests. Asymptomatic ovarian cysts are usually left untreated, while painful cysts can be managed with birth control pills. Surgery is an option for cysts that don't disappear spontaneously.