Glycoprotein 125 can be high during menstruation, but it can also be related to a number of other factors. Glycoprotein 125 is a glycoprotein derived from the epithelial cells of the body cavity and is one of the tumor markers, mostly found in the serum of patients with ovarian tumors. The causes of elevated glycoantigen 125 mainly include the following aspects: 1. During menstruation, women may have high glycan antigen 125 during menstruation, mainly because there is endometrial stripping during menstruation. So to draw blood for tumor markers, you usually need to avoid the menstrual period. 2. If women have endometriosis, adenomyosis, ovarian chocolate cysts, if the blood is drawn during pregnancy, the situation of high Glycoantigen 125 may occur. 3. Malignant tumors, such as ovarian cancer, liver cancer, gastric cancer, lung cancer, etc., may also have significantly elevated Glycoantigen 125. If GAC 125 is significantly elevated during menstruation, further examination is needed to rule out malignant tumors.