The causes of nasal bleeding are many and complex, generally divided into local and systemic. 1, local factors are: trauma, such as trauma to the nose and sinuses, fractures, surgery, skull base fractures, etc.; nasal mucosa stimulation or injury, such as digging, severe coughing, sneezing, forceful pinching, nasal foreign body, chemical dust, smoke, gas, changes in air pressure (such as diving, high-altitude flight, hyperbaric chamber, etc.); inflammation, infection, such as acute and chronic rhinitis, sinusitis, dry rhinitis, atrophic rhinitis and special infections ; nasal septal deviation and ulcer, the most common causative factors of nasal bleeding; tumors, such as nasopharyngeal carcinoma, nasopharyngeal fibroadenoma, nasal hemangioma, malignant tumors of the sinuses; post-gas dryness can also lead to nasal bleeding. 2, systemic factors are: chronic nephritis, arteriosclerosis, emphysema, mitral stenosis, right heart dilatation, thoracic mediastinum and neck tumors can lead to increased venous blood pressure and nasal bleeding; blood diseases, such as hemophilia, aplastic anemia, blood leukemia, thrombocytopenic purpura, etc. can lead to nasal bleeding; liver and spleen diseases and rheumatism, nutritional and vitamin deficiencies, acute febrile diseases or infectious diseases The poisoning of chemicals can also cause rhinorrhea; hereditary hemorrhagic capillary dilation, with a family history of hereditary bleeding-prone disease, dilated and ruptured bleeding nasal mucosal veins, can cause recurrent rhinorrhea; other causes such as endocrine disorders and menstruation are all causes of rhinorrhea. According to statistics, among patients with rhinorrhea, systemic causes account for 1/2, local causes account for 1/4, and unknown causes account for 1/4. Some statistics also show that systemic and local causes each account for 1/2. The difference in results may be related to the different examination methods and categorization of each person. When a person has a rhinorrhea, how to consider the possible causes of the bleeding? Generally speaking, adolescents tend to have localized causes and febrile diseases, while the elderly or chronically ill tend to consider systemic causes, and there are ten nosebleeds for which it is difficult to find the exact cause. When nasal bleeding occurs, the doctor should generally go to the hospital for examination. Based on the medical history and examination, the doctor should, on the one hand, stop the bleeding quickly and, on the other hand, find out the cause of the bleeding and treat it according to the cause.