Chronic gastritis can cause weight loss. Chronic gastritis is divided into chronic superficial gastritis, chronic atrophic gastritis and chronic erosive gastritis. Chronic superficial gastritis does not affect the digestion and absorption of food because the lesions are mild, so there is usually no weight loss. The main reasons for chronic atrophic gastritis and chronic erosive gastritis can cause wasting are: 1. reduced gastric acid secretion: chronic atrophic gastritis is mainly due to the reduction of gastric mucosal glands and atrophy, resulting in reduced gastric acid secretion, the food eaten cannot be decomposed, digested and absorbed by gastric acid, thus affecting the body’s utilization of nutrients in food and leading to wasting. 2. chronic erosive gastritis: due to the gastric mucosa The mucosal surface has a large gastric mucosal damage or even bleeding. When the stimulation of food after eating can appear nausea, vomiting, and even vomiting blood and other performance, repeated vomiting caused by the food can not enter the gastrointestinal and wasting.