Acute upper gastrointestinal bleeding refers to acute bleeding caused by lesions of the esophagus, stomach, duodenum and pancreatic duct and bile duct above the flexural ligament, and bleeding due to lesions of the upper jejunum near the anastomosis after gastrojejunostomy also falls into this range. It is a common clinical emergency with the main clinical manifestations of vomiting blood and blood in stool, or bloody fluid seen in the gastric duct, with an annual incidence of between 50 and 100/100,000. The disease is characterized by vomiting blood and black stools, and the decrease in blood volume can lead to changes in the peripheral circulation. Depending on the amount of blood loss, it can be classified as massive bleeding (bleeding up to 1000 ml in a few hours with acute peripheral circulation failure), overt bleeding (vomiting of blood and/or resolution of tarry black stools without acute peripheral circulation failure) and occult bleeding (positive stool occult blood test). A comprehensive diagnosis of acute upper gastrointestinal bleeding includes a determination of the cause, site, and severity. The role of past medical history and symptoms and signs in the etiologic diagnosis should be emphasized. For example, peptic ulcers often have a history of recurrent epigastric pain, and antacid and antispasmodic drugs can often stop the pain; stress ulcers often have a clear history of trauma; patients who have undergone major gastrectomy should consider the possibility of bleeding from anastomotic ulcers; patients with cirrhotic portal hypertension often have a history of schistosomiasis or hepatitis, and previous barium swallowing examination shows esophagogastric fundic varices; patients with malignant tumors mostly have weakness, loss of appetite Patients with malignant neoplasm often have weakness, loss of appetite, wasting, anemia and other manifestations; patients with biliary tract bleeding often have a triad of right upper abdominal pain, jaundice and vomiting blood. It should be noted that some patients may not have any conscious symptoms before the occurrence of acute upper gastrointestinal bleeding, so it is necessary to rely on auxiliary examinations such as gastroscopy and B ultrasound to clarify the site and cause of bleeding. Fiberoptic gastroscopy is the preferred method to diagnose the cause of upper gastrointestinal bleeding, not only to detect the site and cause of bleeding, but also to help determine the possibility of rebleeding and decide whether emergency surgery is needed. Studies have shown that emergency gastroscopy within 24 hours of onset can clarify the cause as soon as possible, reduce the need for blood transfusions and the chance of surgery, and shorten the number of days in the hospital. Approximately 20% to 35% of patients undergoing gastroscopy require endoscopic treatment with local hemostatic measures such as electrocoagulation, laser, drug injection or metal titanium clamp closure, and 5% to 10% of patients eventually require surgical treatment. The principles of management include effective fluid resuscitation, monitoring of bleeding signs, and etiologic treatment. Due to the continuous improvement of various hemostatic methods, about 80% of patients with upper gastrointestinal bleeding can be treated non-operatively to achieve hemostasis. For upper gastrointestinal hemorrhage of unclear location, if it is not effectively controlled after active initial treatment and the vital signs are still unstable, early emergency dissection should be performed in order to find the cause and stop the hemorrhage completely.