The complications of pulmonary alveoli are as follows: 1. Spontaneous pneumothorax is the most frequent complication in patients with pulmonary alveoli. It is often produced by violent coughing, breath-holding or exercise, which causes a sudden rise in intrapulmonary pressure, leading to rupture of the pulmonary alveoli and the entry of gas into the pleural cavity from the lungs. The clinical manifestations of patients are sudden onset of chest pain, wheezing, coughing and difficulty in whistling. Physical examination reveals a bulging sound on percussion of the affected side of the chest and a weakened or absent whistling sound on auscultation, and in severe cases, a displacement of the trachea to the healthy side. The severity of the patient’s symptoms depends on the amount of pneumothorax and whether it is associated with underlying lung disease. The most common type of spontaneous pneumothorax is a spontaneous pneumothorax without previous underlying lung disease, called primary spontaneous pneumothorax. Most of the patients are tall, thin young men, and the onset of the disease is often without obvious cause, manifesting as sudden onset of dyspnea and chest pain. The vast majority of primary spontaneous pneumothorax is surgically confirmed to be caused by rupture of large pulmonary alveoli or small subpleural vesicles. 2, acute spontaneous hemopneumothorax A small number of patients with large pulmonary alveoli can develop sudden spontaneous hemopneumothorax, generally due to the tearing of the pleural cavity adhesion zone when the pneumothorax occurs, which is caused by the rupture of small blood vessels. In addition to pneumothorax symptoms, patients may also have symptoms of blood loss such as dizziness, palpitations, and pallor. Chest radiography reveals a flattening of fluid pneumothorax in the pleural cavity. Some patients show progressive hemothorax, the condition is dangerous and needs urgent treatment. 3.Secondary infection The lung alveoli cavity is filled with inflammatory material when the alveoli are secondarily infected, which can make the cavity disappear or form liquid air flat. The patient develops cough, coughing, chills and high fever, and the existing wheezing symptoms are aggravated. Clinical differentiation from lung abscess or cavitary tuberculosis is required.