Bronchoscopy is required in the following cases: 1. benign or malignant tumors at the bronchi of the lung can be confirmed by biopsy and pathological examination through this microscopy. 2. pulmonary tuberculosis, such as tuberculosis spheres and tuberculosis cavities can be examined through bronchoscopy. 3. unexplained cough with blood in the sputum or massive hemoptysis can be treated through bronchoscopy or even intervention. 4. imaging examinations such as CT reveal a restricted shadow in the lung, the nature of which is to be determined. 5. The diagnosis can be confirmed by bronchoscopy. 5. Patients with pulmonary atelectasis and obstructive pneumonia are also diagnosed. 6. Diagnosis of lung infections. 7. Bronchoscopy is required for hoarseness and persistent cough.