Recognition of upper gastrointestinal bleeding includes bleeding-related symptoms, decreased hemoglobin volume, positive gastric fluid occult blood, positive fecal occult blood, etc. The definitive diagnosis of etiology relies on its history and gastroscopy. The immediate clinical manifestations of upper gastrointestinal bleeding are blood in vomit, black stools, or blood in the stool, and anemia-related symptoms such as dizziness, palpitations (rapid heartbeat), black haze, fainting, fatigue, and sweating of varying degrees of severity may occur with excessive bleeding. Blood tests after upper gastrointestinal bleeding may show a decrease in the amount of hemoglobin and a positive occult blood test in gastric fluid, vomitus or stool. The final diagnosis of the cause and location of bleeding depends on gastroscopy and history. Upper gastrointestinal bleeding should be treated promptly to avoid delay.