Pulmonary blisters are air-containing saccular cavities larger than 1 cm in diameter in the lung tissue that form when the pressure in the alveolar cavities rises due to various causes and the walls of the alveoli rupture and fuse with each other. Pulmonary maculopapulars are usually secondary to inflammatory lesions in the small bronchi, such as pneumonia, tuberculosis, or emphysema. Some pulmonary macules are caused by congenital genetic abnormalities. There are also a number of idiopathic pulmonary macules of unknown etiology. Lung blisters can be single or multiple. Those secondary to pneumonia or tuberculosis are often single; those secondary to emphysema are often multiple, and the boundary between the large blisters and the surrounding emphysema-like changes in the lung tissue is often unclear. Lung blisters are most commonly located in the apical part of the lung and the edge of the upper lobe of the lung. The patient’s symptoms are closely related to the number and size of the blisters and the presence or absence of other lung diseases. Smaller, fewer simple pulmonary blisters may be asymptomatic and are sometimes detected only incidentally on chest radiograph or chest CT. Large or multiple pulmonary blisters may cause chest tightness and shortness of breath, and a few patients with pulmonary blisters have hemoptysis and chest pain. The discovery of pulmonary blisters should be promptly consulted.