Possible causes of vague pain in the stomach when hungry include: peptic ulcer, chronic gastritis, gastric cancer and so on. 1. Peptic ulcer: peptic ulcer is an inflammatory defect of gastroduodenal mucosa caused by imbalance between gastric mucosal barrier and gastric acid pepsin, which is closely related to Helicobacter pylori infection. Gastric ulcer is mostly manifested as postprandial epigastric pain, while duodenal ulcer is mostly manifested as epigastric pain during hunger, which can be easily mistaken for gastric pain due to the fact that duodenum is adjacent to the stomach. 2. Chronic gastritis: chronic gastritis is a chronic lesion of the gastric mucosa, associated with Helicobacter pylori infection, gastroduodenal reflux, autoimmunity and other factors. It mostly manifests as non-specific digestive symptoms, such as abdominal distension, epigastric discomfort, dull pain, loss of appetite, acid regurgitation and belching, etc. It may also have hidden pain when hungry. 3. Gastric cancer: In the early stage of gastric cancer, there are no obvious specific symptoms, such as abdominal discomfort, vague pain, anorexia, fatigue, etc., but the abdominal pain is not obviously regular. Those who have long-term chronic gastritis or gastric ulcer history should be alert to the possibility of cancer. It is recommended to go to the hospital as soon as possible to improve the relevant examinations such as gastroscopy, to clarify the cause of the disease as soon as possible and then give targeted treatment.