A cough with blood often releases a number of signals that should be taken into account to attract some attention. It may come from a general physiological phenomenon or it may be a previous manifestation of a disease. If the cough is violent, causing congestion and edema in the throat and the rupture of relatively small capillaries, the presence of blood is usually not a cause for too much stress and the blood can be quickly eliminated with timely treatment of the underlying disease. In addition, it is important to be alert to specific diseases, such as tuberculosis, which is one of the types of tuberculosis. The infection of Mycobacterium tuberculosis causes damage to the lungs, resulting in coughing, coughing and blood in the sputum. This can be clarified by relevant tests, such as imaging, tuberculin test and sputum examination. For patients who have been smoking heavily for a long time, they should be highly alert to the occurrence of cough with blood in sputum. The occurrence of lung cancer needs to be clarified by imaging of the lung, such as CT examination, and the appropriate treatment will be given according to different situations.