Ovarian cysts can elevate CA125, a marker of tumor, which is mainly found in patients with ovarian epithelial cancer, such patients will find CA125 higher than normal level during physical examination. However, under some special circumstances, CA125 may also be elevated in women, such as pelvic inflammatory disease, endometriosis, ovarian cysts, etc., especially in women under 50 years old, so after such women found to have elevated CA125, it may not necessarily be ovarian cancer, and further diagnosis should be made according to the patient’s clinical manifestations and ultrasound examination. If a patient is found to have ovarian tumor with elevated CA125 and is over 50 years old, she should be observed.