A small solid lesion in the lingual segment of the left upper lung is usually due to the loss of gas in the lungs due to atelectasis and alveolar effusion, with substantial changes in the lung tissue, and is characterized by increased density of the lung parenchyma on CT, which masks the vascular and bronchial wall imaging. Lung parenchymal changes are usually caused by bacterial or fungal infections in this area, while other common causes such as pulmonary edema, pulmonary hemorrhage, and lung tumors should also be considered. The pathology of solid lung changes is the accumulation of plasma, fibrin, and cellular components in the alveolar cavities for any reason, resulting in a decrease in alveolar air volume and a densification of the lung texture. When such changes occur, it is necessary to combine the patient’s clinical manifestations and other examination results to comprehensively determine the cause of the disease, and if necessary, the feasibility of electronic bronchoscopy to further clarify the diagnosis. Therefore, when the examination found that the reality of changes in the lungs should be timely medical further examination and treatment, so as not to delay the condition.