Gastritis is a common disease in clinical practice, generally divided into chronic gastritis and acute gastritis. Acute gastritis is most commonly characterized by abdominal pain, nausea, and vomiting. The symptoms of chronic gastritis vary and mainly include discomfort in the abdomen, nausea and vomiting, decreased appetite, and even early satiety. For the diagnosis of chronic and acute gastritis, the preferred examination is gastroscopy. Gastroscopy includes both conventional and painless procedures, both aimed at examining the condition of the gastric mucosa. However, for some elderly patients, particularly those with underlying conditions like coronary heart disease, the risk associated with gastroscopy is higher. Therefore, if conventional or painless gastroscopy is not suitable for the patient, abdominal CT and upper GI barium meal can be chosen instead. After completing the gastroscopy, if chronic gastritis or gastric ulcers are diagnosed, it is advisable to further conduct tests to screen for Helicobacter pylori.