Sputum is a kind of garbage in the respiratory tract, which contains self-secreted mucus, cells shed inside the lungs, necrotic tissues and purulent secretions, etc. There are several common reasons for spitting up black sputum in the morning: First, serious air pollution, a large amount of dust, haze, tiny particles in the air due to inhalation into the lungs. Second, the work environment due to the lack of protective measures, such as coal and mining workers, boiler workers and personnel exposed to large amounts of dust. Third, a large number of long-term smokers. The above three factors can be inhaled too much charcoal end, iron end, dust, so that the lungs appear a lot of carbon black accumulation, so the appearance of sputum is black. It may also be a problem on its own side, old small airway rupture, bleeding and bronchial secretions mixed can also have black sputum coughed up, for the external environment caused by spitting black sputum should strengthen the daily work protection, work or go out with a mask to strengthen protection. For self-caused causes such as long-term smokers should take the initiative to quit smoking, and it is recommended that middle-aged and elderly people should do a health checkup once a year to take preventive measures for the problems found in time to ensure that they do not drag into diseases.