Most respiratory diseases have coughing and sputum symptoms. Sputum can be grayish-white mucus sputum or yellowish-green pus sputum, and sometimes coughing up sputum with bright red blood is called hemoptysis. In medicine, bleeding from the trachea, bronchus or lung tissue below the larynx and expelled from the body through coughing is called hemoptysis. Instrument examination 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.Radioactive radionuclide gallium examination: it helps in the differential diagnosis of lung cancer and other lung masses. Blood spit out through the mouth is not always hemoptysis. Hemoptysis should be distinguished from oral or nasal bleeding or vomiting blood from the upper gastrointestinal tract. Blood from the mouth is often mixed with saliva, and examination of the oral cavity can reveal bleeding places, so differential diagnosis is generally not difficult. Careful examination of the nasal cavity is required to detect lesions and bleeding spots. It is sometimes difficult to distinguish vomiting from hemoptysis. Before vomiting, there is often nausea and epigastric discomfort, and the vomitus may be mixed with food.