Frequent stomach discomfort in the middle of the night is considered to be caused by bad dietary habits, chronic gastritis, duodenal ulcer, gastric cancer and other reasons. 1. Bad dietary habits: Often overeating at dinner and avoiding spicy and stimulating food can also lead to frequent stomach discomfort in the middle of the night. 2. Chronic gastritis: the gastric mucosa is damaged, gastric acid secretion is more, at night time fasting stomach acid, stimulate gastric mucosa and cause gastric discomfort, acid reflux, nausea and other symptoms. 3. Duodenal ulcer: the typical symptoms of this disease are pain at night and pain in empty stomach, which is relieved after eating food, because the stomach acid stimulates the ulcer surface during empty stomach. 4. Gastric cancer: due to the infiltration of cancer cells into local tissues, the vagus nerve is excited at night when sleeping, so the stomach feels uncomfortable at midnight, accompanied by black stools, body dissipation, thinness and anemia and other symptoms. It is recommended to consult doctor in time to find out the cause of the disease and treat it as early as possible in order to avoid delaying the condition.