Pulmonary alveoli, also known as pulmonary alveoli. It is an air-containing cavity larger than one centimeter that forms within the lung tissue as a result of increased pressure in the alveolar cavity from various causes and rupture of the alveolar wall. Most of them are secondary to inflammatory lesions of the small bronchi, which cause edema and narrowing of the small bronchi and partial obstruction of the lumen, so that air can enter the alveoli but not be easily discharged, resulting in increased pressure in the alveolar cavity; if the lung tissue is inflamed at the same time, the lung tissue can be damaged, the pressure in the alveolar wall ruptures, and the alveoli fuse with each other to form a large air-containing cavity. There are congenital pulmonary alveoli and acquired pulmonary alveoli. 1, congenital pulmonary alveoli: is due to the congenital abnormal development of alveoli in infants and children, the abnormal development of cartilage makes the alveoli lose support, the mucosal folds of the bronchi form a one-way live flap, so that the gas only in and out, thus forming pulmonary alveoli. 2, acquired pulmonary alveoli: refers to adults suffering from chronic bronchitis and emphysema for a long time, so that small bronchial inflammatory lesions, resulting in edema, narrowing and even obstruction, the formation of one-way valve, the gas only into not, the following year changed into pulmonary alveoli. The increasing pressure of pulmonary blisters even leads to rupture to form pneumothorax. At the same time, chronic inflammation of the lung tissue destroys the structure of the alveolar wall, causing multiple alveoli to gradually fuse to form large air sacs, known as alveoli. The main risk of large pulmonary alveoli is rupture leading to spontaneous pneumothorax or spontaneous hemopneumothorax, which can compress the lung tissue and make the already dysfunctional lung condition more severe, even leading to life-threatening respiratory failure. Therefore severe pulmonary maculoplasm must be treated aggressively.