Coughing up bloody sputum in the morning is clinically common in inflammatory reactions of the respiratory system, including infectious and non-infectious factors. Infectious factors are often seen in acute upper respiratory tract infections, bronchitis, and pneumonia caused by viruses, bacteria, mycoplasma, chlamydia, Mycobacterium tuberculosis, fungi, and leptospira. Non-infectious factors such as radiation pneumonia caused by radiation exposure, bronchial asthma, cough variant asthma, and bronchiectasis. It is also seen in rare bronchial lung cancer, which damages the mucous membrane of the airways and causes a slight rupture and bleeding of a very small number of capillaries in a relatively small amount, so that the blood-tinged sputum will be coughed up in the morning and the bleeding disappears after coughing.