Lung diseases have different causes and can be caused by infections due to microorganisms such as viruses and bacteria, atmospheric pollution, smoking, inhalation of dust or harmful gases. Some diseases are related to immune and genetic factors. Common symptoms are: cough, sputum, hemoptysis, dyspnea, chest pain, infection or immune-related diseases may be accompanied by fever, the mildness, severity and nature of these symptoms vary depending on the disease and the extent of the disease. Pulmonary x-ray shows mainly reduced peripheral texture and smaller hilar vessels. Less lung texture is associated with congenital development and congenital heart disease. It may also be associated with occlusion or reduction of blood vessels due to acquired disease. It is also associated with long-term emphysema. Reduced lung texture is a sparse, thinning lung texture that is seen in bilateral or unilateral lung fields. It is formed overwhelmingly by the thinning and reduction of pulmonary blood vessels, the so-called pulmonary circulation ischemia commonly seen in tetralogy of Fallot, pulmonary artery stenosis atresia, etc., mainly manifested as a generalized pulmonary texture reduction and reduction of hilar vessels, while in pulmonary arterial hypertension, the hilar vessels expand the peripheral vessels suddenly become thin and reduced, the lung air content is normal, in emphysema, on the one hand, the pulmonary capillaries contract and become thin, on the other hand, the lung volume expands so that the pulmonary texture is dispersed. X-ray shows that the peripheral blood vessels of the lung are sparse and reduced, the hilar vessels may be normal or enlarged, and the air content of the whole lung is high.