Local factors (1) trauma or medical injury to the nose and sinuses: it can cause local injury to small blood vessels and mucosa, and in severe cases, to the anterior septal artery and internal maxillary artery. (2) Inflammation of the nasal cavity and sinuses: various non-specific or specific inflammation of the nasal cavity and sinuses can cause bleeding due to mucosal lesions that damage blood vessels. (3) Tumors: Malignant tumors of the nasal cavity, sinuses and nasopharynx ulcerate and bleed through the nose. (4) Other: nasal septal lesions: nasal septal deviation, nasal septal erosion, ulceration or perforation are the common causes of bleeding, nasal foreign body, etc. Systemic factors (1) Acute febrile infectious diseases. (2) Cardiovascular disease. (3) Blood disorders. (4) Nutritional disorders or vitamin deficiencies. (5) Chronic diseases of liver and kidney or rheumatic fever. (6) Poisoning. (7) Hereditary hemorrhagic capillary dilation. (8) Endocrine disorders.