A hemoptysis is defined as a bleeding volume greater than 600 ml in 24 hours, while a fatal hemoptysis is defined as: a hemoptysis volume greater than 150 ml/hour; or a bleeding volume of 300-400 ml each time. many hemoptysis occur outside the hospital, so it is essential to have the necessary knowledge of self-help treatment! Often, time can be gained for professional medical assistance. The causes of hemoptysis are complex and there are several diseases that cause hemoptysis as follows. 1. respiratory diseases such as bronchiectasis, bronchio-pulmonary inflammation, tuberculosis, tumors, etc.; 2. pulmonary vascular diseases such as pulmonary vascular disease and pulmonary embolism; 3. cardiovascular diseases such as heart valve disease and cardiac insufficiency due to various causes; 4. systemic diseases such as blood disorders, autoimmune diseases and lung injury, hereditary hemorrhagic capillary dilatation, diffuse intravascular coagulation, etc.; 5. other diseases such as endometrial ectopic disease, infectious diseases such as epidemic hemorrhagic fever, etc. 6. The above diseases, such as tuberculosis, bronchiectasis, lung cancer and pneumonia, are most likely to cause hemoptysis. Patients should not panic or become emotionally stressed when hemoptysis occurs, as this can aggravate the bleeding. Before going to the hospital, patients and their families can take the following measures at home: 1. Prevent asphyxiation: This is the most important measure. The main cause of death from hemoptysis in a short period of time is not excessive blood loss but the failure to induce blood in time, resulting in obstruction of the airway and death by asphyxiation. If the hemorrhage is known to be in the left or right lung, the patient should be placed in a head-down position with the affected side underneath; if the hemorrhage is not known to originate from which side of the lung, the patient can be placed in a head-down position with the feet high. 2.When the patient is nervous, give appropriate comfort to stabilize the emotion; 3.If the patient is excessively nervous, take sedative drugs, such as Valium, according to the condition; 4.Take to the hospital as soon as possible for emergency treatment.