What Is a Normal Reading for a CA-125 Blood Test?

By Staff WriterLast Updated Apr 6, 2020 8:56:03 AM ET

A normal reading for a CA 125 test measures less than 35 units per milliliter. Higher levels can indicate ovarian, endometrial, peritoneal or fallopian tube cancer, or a benign condition, notes Mayo Clinic.


The CA 125 screening test measures the level of the protein CA 125 in the blood, and it is often used to monitor women who have been diagnosed with ovarian, endometrial, peritoneal or fallopian tube cancer, notes MedicineNet.com. In such cases, a decreasing CA 125 level often indicates that patients are responding to treatment, while a rising CA 125 level may indicate a return or continued growth of the cancer. Several normal and noncancerous conditions can cause an elevated CA 125 level, including endometriosis, liver disease, menstruation, pelvic inflammatory disease, pregnancy and uterine fibroids, explains Mayo Clinic.