The stomach pain in the second half of the night may be due to physiological factors such as diet, or pathological factors such as duodenal ulcer and chronic gastritis. 1. Physiological factors: If you eat too much cold, spicy and stimulating food or fried food that is difficult to digest, or eat too fast, overeating and other behaviors, it will stimulate the gastric mucosa, leading to a vague pain in the stomach in the second half of the night. When sleeping at night, the abdomen is cold, may also lead to gastrointestinal intestinal spasm, appear in the middle of the night stomach pain feeling. 2. Duodenal ulcer: Duodenal ulcer is typically characterized by hunger pains, which usually occur at night. The patient’s pain is also cyclical, usually related to the season, often in the fall and winter or winter and spring. 3. Chronic gastritis: the relative excitement of the parasympathetic nerves at night will lead to an increase in the secretion of gastric acid, so that the damaged gastric mucosa is stimulated, resulting in pain, the patient will have the symptom of a vague pain in the stomach in the second half of the night. There are many other causes of stomach pain in the second half of the night, if the patient has a long-term or repeated stomach pain in the second half of the night, it is recommended to consult a doctor in a timely manner, to identify the cause of the disease, targeted treatment, so as not to delay the condition.