What is chronic atrophic gastritis? The stomach wall is covered with gastric mucosa, and the gastric glands in the mucosa secrete gastric juice, which contains gastric acid, pepsinogen and mucus. Gastric acid activates pepsinogen, which “transforms” into pepsin, thus playing a role in digesting food, while mucus neutralizes gastric acid and weakens the erosion of gastric mucosa by pepsin, thus playing a role in protecting gastric mucosa. When the volume of gastric glands atrophies or decreases in number, it leads to insufficient secretion of gastric juice. On the one hand, pepsinogen is reduced, which causes symptoms such as indigestion and abdominal distension. On the other hand, when the secretion of mucus is reduced, it cannot effectively block the attack of pepsin on the gastric mucosa, and the damaged gastric mucosa will become inflammatory and necrotic, accompanied by symptoms such as heartburn and burning pain, and the gastric mucosa will slowly atrophy over time. In addition, the damaged gastric mucosa is also susceptible to intestinalization, which means that the normal epithelial cells in the gastric mucosa become diseased and become a new type of cells similar to the epithelial cells in the mucosa of the small intestine (or colon). If the epithelial cells of the small intestine mucosa do not have the function of mucus secretion, if the epithelial cells of the gastric mucosa become cells similar to the epithelial cells of the small intestine mucosa, then these cells cannot secrete mucus and cannot protect the gastric mucosa, and in this case, complete intestinal epithelial metaplasia has occurred. If the cells become similar to colonic mucosal epithelial cells, these cells can still secrete mucus, but the function of mucus will be greatly reduced, and the gastric mucosa will be easily damaged and inflamed, and this is a case of incomplete intestinal epithelial metaplasia. This leads to a vicious circle, resulting in more and more serious damage to the gastric mucosa. It is especially important to note that incomplete intestinal epithelial hyperplasia is often associated with the development of gastric cancer. The gastric mucosa covers the lining of the stomach and acts like a protective film to prevent stomach acid, pepsin and other components from corroding the stomach lining. However, this protective film is very thin and fragile, and once it is damaged and atrophied, it is difficult to recover; and once the gastric mucosa is intestinalized, it is difficult to be reversed. Over time, it is easy to form chronic atrophic gastritis, and may cause a series of symptoms, including epigastric distention, pain, heartburn, indigestion, etc.. In addition, partial atrophy and inflammation of the stomach body caused by abnormal autoimmune function is also chronic atrophic gastritis. If chronic atrophic gastritis is not treated in time, it may develop into gastric cancer over time. Therefore, if symptoms such as epigastric discomfort, distension, pain, heartburn, indigestion, etc. occur frequently, it is best to go to a hospital as soon as possible to register for a gastroenterology clinic and diagnose what the problem is through gastroscopy, especially when symptoms such as loss of appetite, anemia, weight loss, etc. occur, attention should be paid to first exclude the possibility of malignant tumors such as gastric cancer. Since atrophic gastritis can be asymptomatic, a routine endoscopy may also be considered for people without obvious symptoms who have a family history of gastric cancer or are over 45-50 years old.