Vomiting blood refers to bleeding from the upper gastrointestinal tract, including the stomach and duodenum, and when the bleeding is relatively large, vomiting through the mouth is called hematemesis. The causes of bleeding include ulcer erosion of blood vessels in the stomach wall causing hemorrhage, bleeding from ruptured esophagogastric fundic varices, bleeding from gastric cancer, and bleeding from friction after eating rough food with malformation of blood vessels in the stomach wall. According to the size of bleeding volume, there are different grading as follows: 1. 24 hours bleeding volume <5ml, will not vomit blood, only exist stool occult blood; 2. bleeding volume >50ml, the naked eye can see the stool become black; 3. bleeding volume >250ml, may bleeding vomit blood. Depending on the size of the vomited blood, the impact on the body is different. If the amount of bleeding is less than 400ml, the impact on the body is not too great, only vomiting blood, black stool; if the amount of vomiting blood reaches 400-800ml, the circulation will be affected, which can lead to a rapid heartbeat, weakness, blood pressure drop; a one-time bleeding amount of more than 800ml, in addition to a rapid heartbeat, blood pressure drop, and may even lead to shock, fainting. In case of vomiting blood, the cause of bleeding should be clarified by emergency gastroscopy. If the bleeding is heavy, blood transfusion should be given and treatment should be given for the cause. Bleeding ulcers are treated surgically and also by interventional treatment, in which an arterial puncture is performed through a catheter into the bleeding site and embolization is performed with an embolic agent. For hemorrhage caused by ruptured esophagogastric fundic varices, the bleeding can be stopped by compression with a triple-lumen tube balloon, followed by treatment with growth inhibition and, if necessary, surgery. For bleeding caused by gastric cancer, treatment is decided according to the amount of bleeding, and emergency surgery or interventional treatment is required if the bleeding is very large.