There are many reasons for coughing and vomiting blood, most commonly in the following areas: 1. Bronchial dilatation: the most common. When bronchial dilatation occurs, the alveoli and bronchi become deformed and collapse, tearing the small blood vessels around the bronchi and causing bleeding, so with coughing there will be hemoptysis and vomiting of blood. If the bleeding is not large, it can stop by itself. If the bleeding is large, bronchoscopy is needed to stop the bleeding and injection of hemostatic drugs for treatment; 2. Tuberculosis: there will be long-term low fever, wasting, coughing, coughing and coughing up sputum and blood. If it is indeed tuberculosis that causes spitting up blood, this is treated with anti-tuberculosis drugs. Another aspect of the cause of coughing up blood is a tumor in the lung. This is usually done with a CT scan of the chest, which will clarify whether or not a mass has developed and if the tumor has invaded a blood vessel, then spitting up blood will occur.