Hemoptysis (hemoptysis) is bleeding from the respiratory organs below the larynx that is discharged from the mouth by coughing action Hemoptysis must first be differentiated from oral, pharyngeal, and nasal bleeding Oral and pharyngeal bleeding are easily observed as localized foci of bleeding. Nasal bleeding mostly flows from the anterior nostrils, and the foci of bleeding are often found in the lower part of the anterior nasal septum, which is easier to diagnose. Sometimes the bleeding from the posterior part of the nasal cavity is large and can be misdiagnosed as hemoptysis. The diagnosis can be confirmed if blood is seen to flow down the pharyngeal wall from the posterior nostril by nasopharyngoscopy. The former often has a history of tuberculosis, bronchiectasis, lung cancer, heart disease, etc. Before bleeding, there is a cough, throat itching and chest tightness, and the blood is bright red, mixed with foamy sputum, usually without tarry stools; the latter often has a history of peptic ulcer, cirrhosis, etc. Before bleeding, there is upper abdominal discomfort, nausea and vomiting, etc. The blood is brown-black or dark red, sometimes bright red, mixed with food residue and gastric juice. It is mixed with food residue and gastric juice and has tarry stools, which may persist for several days after the vomiting has stopped. There are different definitions for estimating the amount of hemoptysis. Massive hemoptysis usually refers to hemoptysis of more than 600-800 ml or 300 ml or more per hemoptysis in 24 h. Small hemoptysis refers to hemoptysis of less than 100 ml per hemoptysis; moderate hemoptysis refers to hemoptysis of 100-300 ml per hemoptysis. Concomitant symptoms: (a) Hemoptysis with fever. It can be seen in tuberculosis, pneumonia, pulmonary hemorrhagic leptospirosis, epidemic hemorrhagic fever, bronchopulmonary cancer, etc. (b) Hemoptysis with chest pain: Lobar pneumonia, pulmonary infarction, tuberculosis, bronchopulmonary carcinoma, etc. (3) Haemoptysis with purulent sputum can be seen in lung abscess, cavitary pulmonary tuberculosis, bronchiectasis, etc. Bronchiectasis also has repeated hemoptysis without coughing sputum, and this type is called dry bronchiectasis. (d) Hemoptysis with choking cough can be seen in bronchial lung cancer, mycoplasma pneumonia, etc. (E) Hemoptysis with skin and mucous membrane bleeding Attention should be paid to epidemic hemorrhagic fever and blood diseases. (f) Hemoptysis with jaundice: Pulmonary infarction, leptospirosis should be noted.