The causes that will vomit blood are mainly divided into local and systemic factors. local factors: 1. oral gum bleeding, some people will wake up in the morning and vomit blood. 2. respiratory tract diseases, the most common are dry bronchiectasis and tuberculosis, lung cancer, most of these patients have intermittent coughing and coughing blood symptoms, but some of them are manifested by the direct appearance of vomiting blood. 3. digestive tract diseases, the most common are gastric ulcer, duodenal ulcer, emergency ulcer, acute erosive gastritis, gastric cancer, these patients usually have symptoms of indigestion in the stomach or recurrent epigastric discomfort. As well as vomiting blood after ruptured hemorrhage from esophageal varices and gastric fundic varices, these are commonly associated with cirrhosis after having hepatitis B and alcoholic liver. Blood vomiting can also occur with heavy biliary tract bleeding. Systemic factors such as hematologic disorders, including hemophilia, leukemia, thrombocytopenia, and various coagulation disorders can lead to hematemesis.