There are many reasons for coughing and coughing up blood. First, it is inflammation, such as coughing caused by cold and bronchitis, and coughing up a small amount of blood sputum when the cough is intense, but the amount is not too much, usually 10-20ml/day. Secondly, bronchial dilatation, which has a long course, may cause recurrent hemoptysis and coughing up blood, and when the amount of coughing up blood is more than 100ml each time, the diagnosis can be made clearly by chest CT. Thirdly, bronchopulmonary cancer, bronchopulmonary cancer often involves repeated hemoptysis within a short period of time, and the amount of hemoptysis does not exceed 100ml, which can be diagnosed by chest X-ray and chest CT. Fourth, tuberculosis patients will repeatedly cough up blood, and the amount of hemoptysis usually does not exceed 100ml, often accompanied by afternoon low fever, night sweats, weight loss, etc. Fifth, other causes including blood disorders, bronchial vascular malformation, pulmonary embolism and other diseases can also lead to hemoptysis.