Gastric function three, refers to the serum gastrin, pepsinogen 1 and pepsinogen 2 three, generally recommended once a year check, the specific examination frequency recommended by the specialist doctor according to the patient’s condition. 1. Serum gastrin: a gastrointestinal hormone secreted by cells mainly in the gastric sinus and duodenum, it plays a relatively important role in regulating the function of the digestive tract as well as maintaining the structural integrity of the digestive tract, and it is mainly a marker for atrophic gastritis of the gastric sinus. 2. Pepsinogen: pepsinogen 1 and pepsinogen 2, pepsinogen 1 is mainly a marker of gastric atrophic gastritis, pepsinogen II is mainly a marker of gastric inflammation. From the three tests of gastric function, it can be clarified whether there is a peptic ulcer? Is there atrophic gastritis? Where is the site of atrophy and so on. It can be comprehensively analyzed to assist in the diagnosis of gastric diseases, identify high-risk individuals, and then selectively do further tests such as gastroscopy if there are problems with the screening.