Basically, patients with chronic gastritis will not have elevated carcinoembryonic antigen. Carcinoembryonic antigen is a tumor marker, which is mainly used to detect reproductive tumors and colonic malignancies, and if carcinoembryonic antigen is high or simply one carcinoembryonic antigen is high, it has no clinical significance. For the diagnosis of colon cancer, electronic colonoscopy plus pathological examination is needed, and for the diagnosis of gastric cancer, electronic gastroscopy plus pathological biopsy is also needed, and pathological examination is the gold standard of diagnosis. If a patient with chronic gastritis has a clear pathological examination and is indeed a chronic inflammatory lesion, if it is superficial gastritis, no clinical symptoms can be treated first. If the patient with chronic gastritis is a gastritis with atrophic gastric mucosa, i.e. chronic atrophic gastritis, he/she needs to cooperate with the physician to give active treatment, such as eradication of Hp or use of gastric mucosal protective agents. Patients with atrophic gastritis must follow up closely with the doctor’s orders. When severe atypical hyperplasia occurs, that is, when the gastric mucosa undergoes cellular degeneration into severe atypical hyperplasia, prophylactic surgery is required.