The first reason for vomiting blood is the following: 1. oral problems: oral problems are commonly caused by bleeding gums, cheek mucosa bleeding, spitting out saliva containing blood. 2. pharyngeal problems: problems with the back wall of the throat are mainly caused by inflammation of the throat causing a foreign body sensation in the throat, followed by vomiting blood. 3. tracheal problems: bronchial problems, first accompanied by coughing, blood in sputum, bright red, accompanied by chest pain, occasional fever. 4. . 4, gastrointestinal problems: the performance of gastrointestinal bleeding is mainly nausea, vomiting, vomit with blood, in most cases the vomit is coffee-colored performance, some accompanied by black stool. Therefore, vomiting blood should be distinguished from oral cavity, throat, trachea, or digestive tract problems.