Atrophic gastritis type A, also known as autoimmune atrophic gastritis, is a disease caused by autoimmune system disorders with atrophy of the gastric mucosa as the main lesion. Atrophic gastritis can be categorized into type A atrophic gastritis and type B atrophic gastritis depending on the cause of the disease, of which type A atrophic gastritis is also known as autoimmune atrophic gastritis. Type A atrophic gastritis is a chronic gastritis that occurs on the basis of autoimmunity and is characterized by atrophy of the gastric body. Autoantibodies such as mural cell antibodies and internal factor antibodies exist in the patient’s body, which not only attack the mural cells in the gastric mucosa, causing the glands in the gastric mucosa to atrophy, reducing gastric acid secretion, and affecting the digestive and absorptive functions of the stomach, but also cause a lack of internal factor, leading to malabsorption of vitamin B12 and causing pernicious anemia. Patients with type A atrophic gastritis mainly manifest abdominal pain and bloating, loss of appetite, postprandial fullness, belching and other symptoms of indigestion and anemia such as pallor. Patients with type A atrophic gastritis are advised to consult a doctor in time and receive treatment actively to avoid delaying the condition.