Belching (burping) accompanied by acid in the mouth may be caused by gastritis, dyspepsia, reflux esophagitis and other diseases caused by poor gastrointestinal motility, acid reflux and other symptoms. 1. Gastritis: Gastritis refers to the inflammatory reaction that occurs when the gastric mucosa is stimulated by various irritating factors in the stomach. Common symptoms include epigastric distension, belching, nausea, acid reflux and so on. 2. Indigestion: The intake of excessively greasy food, spicy and stimulating food, indigestible food, as well as smoking and alcoholism and taking stimulating drugs will cause stimulation of the gastrointestinal mucosa, causing insufficient peristalsis and abnormal secretion of digestive juices, which will lead to the symptoms of belching and acid reflux. 3. Reflux esophagitis: Due to irritation, the contents of the stomach and duodenum reflux into the esophagus, causing ulcerative and erosive inflammatory reactions in the esophageal mucosa. The main symptoms of this disease are heartburn and reflux, but belching and acid reflux may also occur. In addition, Helicobacter pylori infection may also cause belching with acid reflux. It is recommended to go to a regular hospital for examination as soon as possible, and to carry out targeted treatment after determining the cause of the disease.