Alveoli are generally not easy to cause blood in sputum, the specific whether to cause blood in sputum is based on the cause of the disease and the degree of morbidity to decide can not be generalized. 1. For patients with mild pulmonary alveoli, there are usually no clinical symptoms, even if the patient has a slight chest tightness, fatigue, a little coughing, it is less likely to lead to rupture of blood vessels on the surface of the alveoli and cause blood in sputum symptoms. 2. For patients with large pulmonary alveoli, when coughing or exercising strenuously or holding their breath, it may cause localized rupture of the alveoli, or secondary infection, secondary pulmonary heart disease, etc. It may also lead to blood in the sputum, but generally the amount of blood coughed up is not large. No special treatment is needed for asymptomatic alveoli. When symptoms such as dyspnea or infection and blood in sputum are more obvious, it is necessary to complete the relevant examinations in a timely manner to exclude other diseases and take active surgical treatment measures to avoid delaying the condition. Usually pay attention to improve the lifestyle, quit smoking and alcohol, avoid exposure to second-hand smoke, avoid inhaling polluted air.