High cancer antigen 125 may be caused by physiological reasons, ovarian cancer, pancreatitis, tumor recurrence after surgery and so on. 1. Physiological reasons: CAP 125 has certain characteristics of human embryonic antigen, pregnant women may have physiological high CAP 125 in early pregnancy due to embryonic development. 2. Ovarian cancer: CAP 125 belongs to tumor marker, 80% of ovarian cancer patients have elevated serum CAP 125 level, and elevated CAP 125 should be further examined, such as gynecological ultrasound, pelvic MRI, CT and so on, to investigate whether there is ovarian cancer. 3. Pancreatitis: benign diseases may also lead to elevated CAP 125, such as pancreatitis, due to inflammation stimulation, sometimes it will lead to mild elevation of serum CAP 125 level, generally, after treating pancreatitis by fasting and rehydration, the situation of high CAP 125 will be improved. 4. Postoperative tumor recurrence: tumor markers of patients with rectal cancer, gastric cancer and other tumors will generally decrease after surgical treatment, and if high CAP 125 occurs in the process of rechecking, one should be alert to postoperative tumor recurrence. Higher cancer antigen 125 is also seen in pancreatic cancer, gastric cancer, rectal cancer, hepatitis and other diseases. Patients with high cancer antigen 125 should go to the hospital in time, complete the examination, and give targeted treatment after clarifying the cause of the disease.