Coughing up blood in sputum may be tuberculosis, bronchiectasis, bronchopulmonary cancer, pneumonia, lung abscess, pulmonary hypertension and pulmonary embolism and other diseases. 1. Tuberculosis: common in young and middle-aged people, the mechanism is mainly tuberculosis lesions increase capillary permeability, blood exudation, resulting in sputum with blood or small clots; such as small blood vessel rupture can appear in a moderate amount of hemoptysis; such as the formation of small aneurysm rupture, can cause hemoptysis, life-threatening, common in cavitary type tuberculosis. 2. Bronchial dilatation: common in young and middle-aged people, now it is believed that 50% to 70% of patients with bronchial dilatation can have hemoptysis, which can be blood in sputum or small or medium amount of hemoptysis, and hemoptysis can be caused by erosion of small arteries or destruction of proliferated blood vessels. 3. Bronchopulmonary cancer: often manifested as blood in sputum, hemoptysis is less common. 4. Pneumonia: chronic bronchopneumonia and mycoplasma pneumonia can appear bloody sputum or sputum with blood, often accompanied by violent cough. 5. Lung abscess: some patients with chronic lung abscess may have chronic cough, sputum, repeated hemoptysis, fever and other manifestations, often manifested as hemoptysis. 6. Pulmonary hypertension and pulmonary embolism: pulmonary hypertension due to mitral stenosis is more common, followed by pulmonary embolism, etc., which is mainly manifested as small amount of hemoptysis or blood in sputum, pink foamy sputum, etc. The main mechanism is pulmonary hypertension or sputum in the sputum, which is often associated with pulmonary embolism. The main mechanism is pulmonary arterial hypertension or pulmonary embolism caused by pulmonary stasis, resulting in alveolar wall or bronchial endothelial capillary rupture, as well as rupture of bronchial varicose veins. When coughing up blood in sputum, you should go to a regular hospital in time to get a clear diagnosis and cooperate with the doctor for active treatment.