Collapse of one side of the thorax can be caused by abscess or pleurisy, extensive pleural thickening adhesions and constriction, pulmonary atelectasis, pulmonary fibrosis, chronic fibrous tuberculosis, chronic pulmonary suppuration and other disorders. Etiology: Commonly associated with various pleural diseases and lung diseases. Such as pulmonary atelectasis, pulmonary atrophy, pulmonary fibrosis (pulmonary fibrosis, the name of the disease, that is, the interstitial tissue of the lung consists of collagen, elastin and protein glycans, when the fibroblasts are chemically or physically injured, they will secrete collagen for the repair of the interstitial tissue of the lung, which in turn causes pulmonary fibrosis; that is, after the lung is injured, the body repairs the results produced.) , extensive pleural thickening adhesions, post lobectomy, etc. Examination: Clinical manifestations vary with the primary disease, the trachea shifts to the affected side, the affected side of the thorax becomes smaller, and the spine commonly has healthy lateral convexity. Although there are some differences in the size and shape of normal thorax between individuals, generally speaking, the anterior and posterior diameters of normal adult thorax are shorter than the left and right diameters, and the ratio between them is about 1:1.5. The anterior and posterior diameters of the thorax of children and the elderly are slightly smaller than the left and right diameters or almost equal, so they are cylindrical. Prevention: The thorax is the bony foundation and support of the thoracic wall, consisting of 12 thoracic vertebrae, 12 pairs of ribs and a sternum linked by joints and cartilage. The morphology of each bone of the thorax rib 12 pairs, left and right symmetrical, the back end and thoracic vertebrae related to the joint, the front end only the 1st-7th rib by cartilage connected with the sternum, called the true rib; the 8th-12th rib is called a false rib, where the 8th-10th rib by rib cartilage connected with the cartilage of the previous rib, forming a rib arch, the front end of the 11th and 12th rib free, also known as floating rib. The sternum is a flat bone located in the middle of the anterior wall of the chest, shaped like a short sword, divided into three parts: hilt, body, and saber. When examining, it should start from the anterior chest, then to the lateral chest and posterior back. The thoracic scaffold is composed of the sternum, clavicle, twelve thoracic vertebrae, twelve pairs of ribs, scapulae and other bones. The upper part of the sternum is the sternal stalk, and its upper sides are connected to the clavicle end. When examining the chest wall, in addition to paying attention to the nutritional status, skin condition, lymph node enlargement, muscle development, etc., we should also focus on examining: veins, chest wall, rib space, etc. A normal chest is roughly symmetrical on both sides, oval in shape, and both shoulders are basically at the same level. If you find any inconsistency with the above, seek medical attention and have regular medical checkups every year.