The slightly increased texture of the two lung fields mainly includes the following categories: 1, vascular lung texture increase, lung texture is coarse, from the pulmonary hilar to the lung to maintain the characteristics of the vascular travel, often accompanied by the manifestation of heart enlargement, mainly seen in wind heart disease, precordial heart disease, etc. 2, lymphatic lung texture increase, lung texture in the two lungs, in the form of a slender mesh, commonly seen in pneumoconiosis, cancerous lymphangitis. 3, the increase of smoking lung texture, showing both lung The increased texture, but the travel is normal, mainly due to charcoal end sedimentation caused by long-term smoking. 4, physiological lung texture increase, mainly seen in the elderly and obese people. The former is due to the relative abundance of interstitial lung mass in the elderly, thus showing an increase in lung texture on the x-ray chest film. The latter is due to obesity and increased subcutaneous fat, resulting in increased x-ray absorption, thus causing the illusion of increased lung texture on the chest radiograph.