Gastric acidity and belching are caused by reflux esophagitis, dyspepsia, chronic gastritis, and Helicobacter pylori infection. First of all, the appearance of reflux esophagitis is directly related to abnormal gastric peristalsis, relaxation of the cardia sphincter, and reflux of gastric acid into the esophagus, which causes violation of the esophageal mucosa. When the stomach acid comes in contact with the esophageal mucosa during an attack of the disease, the patient experiences symptoms such as gastric reflux, burning in the sternal area, pain, and belching. Secondly, in the case of indigestion, the food will remain in the stomach because the time to expel it will be limited, and the food will stimulate excessive secretion of gastric acid during the stay, which will lead to symptoms such as gastric acidity and belching. Then some people suffer from chronic gastritis, which can stimulate the gastric glands due to inflammation in the gastric mucosa, leading to excessive secretion of gastric acid and inducing symptoms such as gastric flushing and belching. Finally, Helicobacter pylori is a harmful bacterium that, when living in the stomach, metabolizes toxins that cause irritation to the mucous membrane of the stomach wall and changes to the environment of the stomach.