Acute upper gastrointestinal bleeding refers to bleeding caused by lesions in the gastrointestinal tract above the suspensory ligament of the duodenum mainly including the esophagus, stomach, duodenum, bile duct and pancreatic duct. According to the etiology of bleeding, it is divided into two categories: non-variceal bleeding and variceal bleeding. Most of the clinical cases are non-variceal bleeding, of which the most common etiologies include gastroduodenal peptic ulcer, gastroduodenal erosion, cardia mucosal tear, and malignant tumor of the upper gastrointestinal tract. Mild cases may be asymptomatic, with clinical manifestations mostly consisting of vomiting blood, black stools, bloody stools, and also atypical symptoms such as dizziness, weakness, and syncope. Therefore, patients with acute upper gastrointestinal bleeding must undergo correct, rapid and standardized diagnosis and treatment.