Despite the application of various screening methods to patients with hemoptysis, 5% to 15% of patients still have unknown causes of hemoptysis, called occult hemoptysis. Some occult hemoptysis may be due to non-specific ulcers of the trachea and bronchi, varices, early adenomas, small bronchial stones, and minor bronchial dilatation. Patients with hemoptysis should have a careful and repeated chest examination. Some chronic heart and lung diseases can be combined with disobedient fingers (toes), and patients with progressive tuberculosis and lung cancer often have significant weight loss. What are the laboratory tests for hemoptysis with skin and mucous membrane bleeding? Sputum examination helps to detect Mycobacterium tuberculosis fungi, bacteria, cancer cells parasite eggs, heart failure cells, etc.; bleeding time clotting time, prothrombin time platelet count and other tests help to diagnose bleeding disorders; red blood cell count and proerythrocyte determination help to infer the degree of bleeding, eosinophilia suggests the possibility of parasitic diseases. 1.X-ray examination: all patients with hemoptysis should have X-ray examination, chest fluoroscopy, chest plain film body layer photography, and bronchography to assist in diagnosis if necessary. 2.CT examination: It helps to find small bleeding lesions. 3.Bronchoscopy: Patients with unexplained hemoptysis or bronchial obstruction with pulmonary atelectasis should consider bronchoscopy, such as tumors, tuberculosis foreign bodies, etc., while taking biopsies for pathological examination or foreign body removal, bleeding and sputum aspiration on the same direct vision 4.Radionuclide gallium examination: helps to differential diagnosis of lung cancer and other masses in the lung. Hemoptysis is a common emergency in internal medicine, with complex causes and variable conditions, which can threaten the life of patients in serious cases. If it is urgent, we should treat the symptoms and stop the hemorrhage first. However, treatment for the cause should not be neglected. Hemoptysis is especially common in early spring. If you pay attention to prevention, you can minimize the factors that trigger hemoptysis. Patients with respiratory diseases should pay attention to protection in autumn and winter.