Sudden belching in the middle of the night may be related to physiological factors, or it may be caused by functional dyspepsia, gastroesophageal reflux disease, or pathologic diaphragmatic spasm. 1. Physiological factors: a cold abdomen during sleep, or eating a lot of radish, soy products and other easy to produce gas before going to bed may cause sudden belching in the middle of the night, these are physiological factors, through appropriate abdominal massage, drink some warm water, is conducive to relief. 2. Functional dyspepsia: usually caused by excessive mental tension, anxiety, psychological stress, etc., may lead to sudden belching in the middle of the night, may also be accompanied by abdominal distension, nausea and other manifestations. 3. Gastroesophageal reflux disease (GERD): due to GERD, the lower esophageal sphincter relaxes, resulting in reflux of gastric contents, which can easily lead to an increase in gastric pressure, resulting in abnormal peristalsis of the gastrointestinal tract, which may cause sudden belching in the middle of the night, which may be accompanied by heartburn, epigastric pain and other symptoms. 4. Pathological diaphragmatic spasm: common in the lower lung inflammation, liver abscess, pleural lesions adjacent to the diaphragm, can lead to diaphragmatic stimulation, which may cause sudden belching in the middle of the night. Sudden belching in the middle of the night, may also be caused by other reasons, if accompanied by other obvious symptoms of discomfort, should consult a doctor in a timely manner, after the cause is clear, by the doctor’s guidance for treatment and regulation.