Lung solidification is the imaging term for the replacement of air in the air-containing lumens distal to the terminal fine bronchi by pathologic fluid, cellular tissue. It is common in diseases such as pneumonia, tuberculosis, pulmonary edema, cryptogenic mechanized pneumonia, and lung cancer, some of which can be cured and some of which cannot. 1. Pneumonia: most of the pneumonia can be gradually recovered after active anti-infection and symptomatic treatment, but severe infections can be combined with respiratory failure and other complications and endanger life. 2. Tuberculosis: after active anti-tuberculosis treatment, most cases can be cured, but may leave streaks, calcification and other lung foci, and serious infections may also be life-threatening. 3. Pulmonary edema: for example, cardiac insufficiency can be combined with pulmonary edema. After diuretic and other treatments, pulmonary edema may be completely cured, but when pulmonary edema is serious, it may be life-threatening due to respiratory failure and other complications. 4. Cryptogenic mechanized pneumonia: this disease may be cured after treatment with glucocorticosteroids such as prednisone, but there is a possibility of recurrence. 5. Lung cancer: there is a special type of pneumonia called pneumonia-type lung cancer, which can be manifested as lung solid changes. The disease is generally incurable and usually progresses gradually and becomes life-threatening; however, the condition may be improved after active treatment, and the survival time may be prolonged. Therefore, it is necessary to consult a doctor in time to identify the cause of solid lung changes and give targeted treatment.