Symptoms of purulent pleurisy include cough, fever, chest pain, dyspnea, and its dangers include pleural adhesions, pleural thickening, as well as respiratory failure and heart failure. 1. Cough: mostly manifested as irritating dry cough, caused by various inflammatory mediators acting on the lungs. 2. Fever: one of the common systemic symptoms of pleurisy. 3. Chest pain: generally pinprick pain, especially obvious on both sides of the chest, and there are factors that aggravate the pain, such as coughing and deep breathing, and the pain can be alleviated when lying on the side. 4. Difficulty in breathing: Patients with purulent pleurisy have a large amount of inflammatory exudate in the pleural cavity, which prevents the normal expansion of the lungs and makes it difficult to breathe. It is accompanied by symptoms such as chest tightness, shortness of breath and panic. 5. Pleural adhesion: the dirty layer and the wall layer of pleura are adhered to each other, and the structure of pleural cavity disappears, which seriously affects the lung expansion, and the lung function decreases sharply, leading to respiratory difficulties. 6. Pleural thickening: the thickening of the pleura of the dirty layer and the wall layer, mild thickening does not affect normal life, but serious cases will limit the contraction and diastole of the lungs, resulting in severe dyspnea, and will limit the movement of the thorax, or worse, will cause deformation of the thorax, which affects the respiratory function. It can be treated by surgery. 7. Respiratory failure and heart failure: prolonged pleurisy leads to a large amount of pleural effusion, which causes dyspnea, which leads to a decrease in pulmonary circulation, and the right atrium and ventricle are unable to pump blood into the pulmonary arteries, which leads to stagnation of blood in the right heart, which further develops into heart failure. If septic pleurisy is detected, it is important to seek prompt medical attention and treatment to avoid harm.