<unk>  is a process of chronic inflammation of the gastric mucosa of the stomach, leading to a loss of gastric glandular cells and their eventual replacement by intestinal and fibrous tissues. As a result, the stomach's secretion of essential substances such as hydrochloric acid, pepsin, and intrinsic factor is impaired, leading to digestive problems. The most common are vitamin B12 deficiency which resulting from pernicious anemia and malabsorption of iron, leading to iron deficiency anaemia. It can be caused by persistent infection with Helicobacter pylori, or can be autoimmune in origin. Those with autoimmune<unk>  (Type A<unk>  are statistically more likely to develop gastric carcinoma, Hashimoto's thyroiditis, and achlorhydria. Type A<unk>  primarily affects the fundus (body) of the stomach and is more common with pernicious anemia. Type B<unk>  primarily affects the antrum, and is more common with H. pylori infection.
Atrophic gastritis
Lymphocytic esophagitis
Herpes esophagitis
Tropical ulcer
Gastric lymphoma
Eosinophilic esophagitis
Barrett's esophagus
Cytomegalovirus esophagitis