The main side effects of bronchoscopy are: 1. It may cause misaspiration because the bronchoscope has to pass through the vocal cords, and at the same time, local anesthetics will be used, and some patients may have gastric reflux aspiration into the trachea leading to lung infection; 2. If the person doing the bronchoscopy is not particularly skilled, and the patient’s choking reflex is serious, the bronchoscope may cause damage to the vocal cords when passing through the vocal cords. Therefore, some people’s voice will be hoarse for a period of time after bronchoscopy; 3, postoperative operations, such as some treatment or biopsy after the bronchial cavity bleeding, or even more serious clot obstruction leading to asphyxia; 4, intracavitary laser treatment may even lead to bronchial fistula, or even perforation, but the probability of occurrence has been very low. Nowadays, the main side effect of doing routine bronchoscopy is that the patient feels uncomfortable, nothing more than choking and coughing, sometimes with gag reflex and nausea, but it is generally mild.