The main causes of stomach pain in the afternoon are: 1. dietary factors, mainly due to the consumption of spicy food, indigestible food and alcohol at lunchtime, the stimulation of such food leads to damage to the gastric mucosa, resulting in stomach pain in the afternoon. 2. peptic ulcer, mainly due to duodenal ulcer, due to the emptying of the stomach in the afternoon, stomach acid in the stomach is relatively over-secreted and enters the duodenum to stimulate the ulcer surface, resulting in stomach pain in the afternoon. 3. 3, excessive secretion of gastric acid, mainly due to eating sweet potatoes, sugary foods and acidic foods, mental tension, depression, anxiety and other causes of vagal inhibition, drugs and gastrinoma can lead to increased secretion of gastric acid. Excessive stomach acid can stimulate the gastric mucosa, and even appear to digest itself and lead to peptic ulcer, so there will be the phenomenon of stomach pain in the afternoon.