Chronic inflammation of the gastric mucosa of the gastric sinuses is a common description of gastritis on gastroscopy. The severity is related to the type of chronic gastritis. In the case of non-atrophic gastritis, the prognosis is good with treatment. In the case of atrophic gastritis, especially if accompanied by heterogeneous hyperplasia, there is a risk of transformation into cancer. Chronic gastritis is a chronic inflammatory lesion of the gastric mucosa caused by multiple etiologic factors. According to endoscopic manifestations and pathology, it is categorized into atrophic gastritis and non-atrophic gastritis. Most adults have mild non-atrophic gastritis, which does not even require medication if there is no H. pylori infection or no symptoms. If combined with H. pylori infection or more severe symptoms, the prognosis is good through the eradication of H. pylori, protection of gastric mucosa and other treatments. Chronic atrophic gastritis, also a common disease, is generally not a serious disease if not combined with precancerous lesions such as high-grade intraepithelial neoplasia. Timely consultation is needed for targeted treatment to slow down the progression to gastric cancer to avoid adverse effects.