Upper gastrointestinal (GI) bleeding is very common in clinical settings, and the main causes of upper GI bleeding include the following: First, gastric and duodenal ulcers, esophageal diseases. Second, esophageal and gastric fundal varices rupture caused by portal hypertension. Third, diseases of organs or tissues adjacent to the upper digestive tract, such as biliary bleeding or pancreatic diseases involving the duodenum, such as pancreatic cancer, as well as aortic aneurysms breaking into the esophagus, stomach, or duodenum. Fourth, systemic diseases, such as allergic purpura, hemophilia, etc., can all lead to upper GI bleeding. After such bleeding occurs, it is essential to seek medical attention promptly.