The pathological staging of tuberculous septic chest conforms to the pathological staging rule of common septic chest and is divided into three stages; 1, acute exudative stage The main pathological changes are pleural congestion and edema, and a large amount of plasma-like exudate appears in the pleural cavity, which is thin and clear, containing high protein content, little cellular content, and no fibrin deposition. 2.Fibro-purulent phase A large amount of fibrin deposits appear in the dirty pleura and wall pleura, forming a fibrin layer on the surface of the dirty pleura, which is also the lung, affecting the reopening of the lung. As the exudate is reabsorbed, proteins are deposited in the effusion, forming a honeycomb-like separation of different sizes. The exudate becomes sticky and the number of cells in the pleural fluid increases, mostly lymphocytes. 3, chronic abscess pleura stage The dirty pleura and wall pleura gradually thicken under the stimulation of chronic inflammation, forming thickened fiber plate, new capillaries and fibroblasts grow in, mechanization, hardening, pus cavity between the two layers of fiber plate, which has granulation tissue and thick pus, and cheese-like necrotic material, the surface of diaphragm is often wrapped by fiber plate. The thickened fibrous plates bind the surface of the lung and diaphragm, affecting the movement of the lung and diaphragm, resulting in varying degrees of impaired respiratory function. In general, the thickening of the fibrous plate of the dirty pleura on the surface of the lung is less than that of the fibrous plate of the wall, and in some cases the thickening of the fibrous plate of the wall is more than 3 cm. The thickening of the fibrous plate of the wall, mechanization or even calcification, and contraction of the fibrous plate can cause narrowing of the rib space and collapse of the thorax, which can cause scoliosis in adolescent patients in the developmental stage. Generally speaking, the acute exudative phase is within 2 weeks of onset, the fibrous purulent phase is from 2 weeks to 4 weeks, and the chronic purulent phase is from 4 weeks to 6 weeks later. In fact, the three stages are artificially divided, and there is no strict boundary between them, but a gradual process. Many clinicians are accustomed to call stage I and II as tuberculous pleurisy and stage III as tuberculous pustulosis, which in essence includes tuberculous pleurisy. The pus in chronic tuberculous abscess chest can penetrate outside the chest wall to form a self-inflating abscess chest, and the pus penetrating out of the chest wall can be confined to the chest wall to form a chest wall abscess, or it can penetrate out into the abdomen to form an abdominal wall abscess, or it can flow down the lumbar muscle gap to inject into the lower limbs to form a lumbar muscle abscess and a lower limb abscess. Pus can erode into the ribs and vertebrae to form rib and vertebral osteomyelitis. Pus can also erode into lung tissue, forming foci of caseous necrosis of lung tissue, and if internal drainage is formed through the bronchi, bronchopleural fistula is formed.