Chronic atrophic gastritis (CAG) is a type of chronic gastritis that is characterized by repeated damage to the epithelium of the gastric mucosa resulting in a reduction of intrinsic glands, often accompanied by intestinal metaplasia (IM) and/or heterogeneous hyperplasia (Dys) of the intestinal glands. “(IM) and/or dysplasia (Dys), a chronic gastric disease. Atrophy refers to the reduction of intrinsic glands of the gastric mucosa and is histologically classified into two types: (1) chemogenic atrophy: replacement of intrinsic gastric glands by enteric or pseudopyloric glands; (2) non-chemogenic atrophy: reduction in the number of intrinsic glands caused by replacement of intrinsic glands of the gastric mucosal layer by fibrotic or fibromuscular tissue or by inflammatory cell infiltration.