Gastritis is an alteration of the gastric mucosa, which may be characterized by pathological changes such as congestion, erosion or even hyperplasia of the gastric mucosa. Gastritis can be found through gastroscopy, pathologic examination of the gastric mucosa pathological changes. Such as acute gastritis: gastroscopy can see the gastric mucosa obvious congestion, edema and even ulceration, pathological examination can see obvious inflammatory cell infiltration. Such as chronic non-atrophic gastritis: gastroscopy can be seen gastric mucosal congestion, erosion and other changes, pathological examination can be seen inflammatory cell infiltration. Such as chronic atrophic gastritis: gastroscopy can see the thinning of the gastric mucosa, pathological examination can see the atrophy of the glands and intestinal epithelial hyperplasia, atypical hyperplasia and other changes. For the diagnosis of gastritis, it is recommended that the doctor combine the history, symptoms, gastroscopy and pathology to make a comprehensive judgment.