In clinical practice, bleeding in the digestive system above the ligament of Treitz is referred to as upper gastrointestinal bleeding. It primarily includes the following areas: The first major category is esophageal diseases, such as esophagitis, esophageal trauma, and other causes of bleeding. The second category is duodenal diseases, such as peptic ulcers, acute erosive hemorrhagic gastritis, stomach cancer, etc. Another cause is liver cirrhosis leading to portal hypertension, which can cause rupture and bleeding in esophageal and gastric varices. The fourth category includes biliary system and pancreatic diseases involving the duodenum, such as pancreatic cancer, which can also lead to bleeding.