Nausea and vomiting at night are associated with chronic gastritis, indigestion, and pyloric obstruction. When there is chronic gastritis in the stomach, the digestive function of the stomach will be damaged, and excessive food intake during the day will lead to an increased burden on the digestive system, which will be relatively serious at night, resulting in nausea and vomiting. Some people will have indigestion and will not be able to eliminate the food in time, especially at night when a large amount of indigestible food is consumed, the food will not be emptied and will cause irritation to the stomach wall, resulting in nausea and vomiting. When pyloric obstruction occurs, the discharge of food from the stomach will be restricted, and at night, the food consumed during the day will not be emptied in time and will accumulate and ferment in the stomach. Many people will excrete the food consumed during the day by vomiting at night to relieve the pressure in the stomach.