Gastric mucosal thickening is one of the clinical manifestations of “chronic atrophic gastritis” (intestinal, atypical hyperplasia), which is a common gastric disease. Arteriosclerosis, inadequate gastric blood flow, and tobacco, alcohol, and tea addiction can easily damage the barrier function of the gastric mucosa and cause chronic atrophic gastritis. In atrophic gastritis, the gastric mucosa atrophies and is replaced by epithelial cells of the intestine, i.e., intestinal metaplasia; as the inflammation continues to evolve, the cells grow atypically, i.e., interstitially, or even proliferate and become cancerous. The clinical diagnosis is mainly as follows. 1. The gastric mucosa becomes lighter in color: light red, grayish yellow, or grayish white or grayish blue in severe cases. It can be diffuse or limited plaque distribution. The peripheral border is indistinct. It is the earliest manifestation of mucosal atrophy microscopically. 2, submucosal vascular penetration: mucosal atrophy makes submucosal vessels visible. Atrophy can be seen in the early stage of mucosa dark red reticulate small blood vessels, severe cases can be seen in the mucosa of blue dendritic larger veins. Vascular exposure is an important endoscopic feature of chronic atrophic gastritis. However, it should be noted that the gastric mucosa can be permeable to the vascular network when the gastric pressure is too high due to hyperinflation of the normal gastric fundus. 3, the mucosal folds are small or even disappear: when the air is injected into the stomach, the folds disappear quickly, and after the air is removed, the folds recover more slowly, and the gastric secretions are small, sometimes the mucosa is dry and the reflection is weakened. 4, gastroscopy and gastric mucosal pathology: when chronic atrophic gastritis is accompanied by transitional hyperplasia of the glandular neck or intestinal epithelial hyperplasia, the mucosal surface is rough and uneven, granular or nodular, sometimes visible pseudo-polyps are formed, and the features of the submucosal vessels revealed are often obscured. Although microscopic visual observation can initially determine intestinal epithelial hyperplasia, the diagnosis must be confirmed by pathological examination of the gastric mucosa.