High carcinoembryonic antigen may be caused by physiological factors, as well as tumors, digestive diseases and other diseases. 1. Physiological factors: Carcinoembryonic antigen is normally less than 5.0μg/L. If you drink a lot of alcohol before the test, or eat too much oily and high protein food, it may affect the test result. In addition, people who have smoked for many years and the elderly may also have high carcinoembryonic antigen. 2. Pathological factors: (1) Tumor: for example, lung cancer, breast cancer, gastrointestinal tract tumor, liver tumor, pancreatic cancer, biliary tract tumor and so on, all of them may cause carcinoembryonic antigen to be elevated, and this index is not specific. (2) Digestive tract diseases: some digestive tract diseases can also affect the rise of carcinoembryonic antigen, such as gastric ulcer, enteritis, pancreatitis, intestinal ulcer, intestinal polyp, intestinal obstruction, biliary obstruction and so on. (3) Others: Carcinoembryonic antigen may also be elevated during the active stage of the disease if the patient has infections or immune diseases. It is recommended to consult the doctor according to one’s own symptoms, and carry out examination under the doctor’s guidance to clarify the cause.