The main reasons for anemia caused by atrophic gastritis are as follows: 1. Patients with atrophic gastritis eat poorly, gastric juice secretion is reduced, and indigestion is easy to occur, so the reduction in nutrient intake can lead to anemia. 2. Patients with atrophic gastritis are mostly combined with Helicobacter pylori infection, which can also cause anemia, and Helicobacter pylori can cause damage to the mucosa, leading to impaired absorption of nutrients. Patients with atrophic gastritis have atrophy of the gastric mucosa and reduced secretion of endogenous factors, which cannot combine with vitamin B12, resulting in the manifestation of anemia, which are the causes of anemia caused by atrophic gastritis. Atrophic gastritis itself has a certain tendency to become cancerous, and if severe anemia occurs it must be ruled out. Therefore, for patients with atrophic gastritis, they must pay attention to regular review of gastroscopy and H. pylori.