There are many causes of coughing up blood, first of all, we should exclude whether there is blood in sputum caused by inflammation of the upper airway, such as whether there is rhinitis, tonsillitis, pharyngitis, and sometimes bleeding gums can also lead to the symptoms of blood in sputum. However, the most common diseases that are considered to be lower airway pathology and most likely to have blood in sputum are bronchiectasis, tuberculosis, and pulmonary malignancy. Bronchiectasis hemoptysis is sometimes larger and has a shorter duration. The symptoms of tuberculosis hemoptysis are mainly recurrent hemoptysis, and of course, there is also a state of hemoptysis. For the diseases that are most likely to have blood in the sputum, the first thing to consider is the possibility of malignant tumors. Therefore, the first step is to identify the cause and improve a series of relevant examinations. The main thing is to take a chest X-ray, preferably a chest CT film, to identify whether there are lesions in the lungs and whether there are abnormal shadows. And the most crucial thing is to perform bronchoscopy to clarify the site of bleeding and the specific cause of the lesion.