Bleeding from the larynx and the respiratory tract and lungs below the larynx, which is coughed up through the mouth, is called hemoptysis. Hemorrhage causing hemorrhagic shock leading to death is relatively rare, but more commonly a large amount of blood floods the alveoli and obstructs the airway, leading to the patient’s death due to asphyxia and intractable hypoxemia. Zhang Shaofu, Department of Respiratory Medicine, Thousand Buddha Mountain Hospital, Shandong Province There is no clear definition of the size of hemoptysis, but it is generally considered that hemoptysis of less than 100 ml per day is a small amount, 100 ml to 500 ml is a medium amount, and more than 500 ml or more than 100 ml of hemoptysis at one time is a large amount. In addition to the amount of hemoptysis, the evaluation of the severity of hemoptysis should be combined with the other manifestations of the patient.