The discomfort in the middle of the chest and acid reflux in the mouth may be related to reflux esophagitis, bile reflux gastritis, gastric ulcer and other diseases. 1. Reflux esophagitis: Reflux esophagitis refers to the inflammatory lesions of the esophagus caused by damage to the esophageal mucosa due to the reflux of the contents of the stomach and duodenum into the esophagus, with clinical manifestations such as heartburn, acid reflux and chest pain. 2. Bile Reflux Gastritis: Bile Reflux Gastritis, also known as alkaline reflux gastritis, is a condition in which bile-containing duodenal contents reflux into the stomach, resulting in inflammatory changes in the gastric mucosa, and the patient usually suffers from heartburn, acid reflux, and vomiting, among other symptoms. 3. Gastric ulcer: After being stimulated by various reasons, the gastric mucosa, which has a protective function in the inner wall of the stomach, may be broken and ulcerated, that is, gastric ulcer is formed, which leads to pain, bloating, heartburn, acid reflux and other symptoms. In addition to the above diseases, the discomfort in the middle of the chest and acid reflux in the mouth can also be caused by other diseases, and it is recommended that the patient improve the auxiliary examination to clarify the condition and carry out timely treatment.