There are many reasons for patients to have blood in cough and sputum, which need to be analyzed and judged with clinical reality, as follows: i. If the blood comes from the throat, consider it caused by upper respiratory tract infection, such as acute pharyngitis and acute tonsillitis, which can show symptoms of blood in cough and sputum, and most of this blood can stop by itself. Second, if the blood comes from below the throat, such as from the bronchi, consider it to be caused by infectious diseases of the lower respiratory tract, such as bronchitis, bronchial dilatation, tuberculosis, in addition to bronchial lung cancer, which can also cause cough and blood in sputum. Therefore, patients with cough with blood in sputum often need to improve lung CT and other related examinations for clarification.