Many patients with adenomyosis treated conservatively need regular gynecologic ultrasound, pelvic examination (anal examination for unmarried, triple examination for married), and serum CA125 testing. Patients often ask anxiously, “Why is the CA125 level so high, is it cancerous? CA125 is a glycoprotein detected by Bast et al. in 1983 from epithelial ovarian cancer antigen that can be bound by the monoclonal antibody OC125. 95% of healthy adult women have CA125 levels ≤ 35 U/ml. CA125 is also called cancer antigen 125, which literally sounds quite scary, but patients with adenomyosis will not be overly anxious and nervous if they really understand its detection value. CA125 is characterized by its high sensitivity, which means that it may be elevated whenever there is some wind in our body, but its specificity is poor. In addition to true obstetrical and gynecological tumors, including ovarian, fallopian tube, endometrial and cervical cancers, malignant tumors in other areas, such as pancreatic, intestinal, breast and lung cancers, may also be elevated. The most important thing that patients need to know is that CA125 is also elevated in benign diseases, such as cirrhosis, acute pancreatitis, pelvic inflammatory disease, etc. In addition, the most common are patients with endometriosis and adenomyosis. CA125 can also be elevated during specific periods in women, such as menstruation and the first trimester of pregnancy. Doctors test CA125 before and after conservative treatment of adenomyosis patients in order to assist in the diagnosis, to understand the severity of the disease, the total load of the lesion and the activity of the lesion, and as an important indicator of the efficacy of the treatment. The patient should not be too anxious to get the test result of CA125 increase, patiently wait until the next follow-up consultation with the doctor is, there are several patients with CA125 test value of more than 2000 adenomyosis had surgery, the pathological examination of the removed uterus is still benign. The first thing you should do is to avoid having your blood drawn during your menstrual period.