Acid reflux at night is caused by reflux esophagitis, chronic gastritis, functional dyspepsia and other diseases. Reflux esophagitis after the disease of the patient’s lower esophageal sphincter relaxation, while sleeping at night is the peak of gastric acid secretion, gastric acid due to the sphincter is relatively relaxed and the phenomenon of gastric acid reflux, and therefore will be manifested in the night spit acid water. Chronic gastritis patients gastric mucosa will be more susceptible to gastric acid stimulation due to inflammation, water, swelling and other factors, the gastric mucosa will be stimulated by excessive secretion of gastric acid at night, the gastric mucosa will be stimulated by the phenomenon of abnormal spasms, so there will be vomiting of acidic water. Some people with functional dyspepsia symptoms, these people’s food emptying function will be affected will not only cause the stomach bloating, but also will be excessive secretion of gastric acid, so it will also be manifested in the night spit acid water.