Nosebleed is a symptom produced by the rupture and bleeding of blood vessels in the nasal cavity, which is seen in rhinitis sinusitis, deviated septum, nasal tumors, systemic diseases and nasal dryness, etc., and is not a precursor of any disease. 1. Rhinitis sinusitis, congestion and edema of the mucous membrane of the nasal cavity and sinuses, rupture and bleeding of the mucous membrane due to nose blowing and other reasons. 2 deviated nasal septum: it will lead to the thinning of the mucous membrane on the deviated side of the nasal cavity, and the airflow stimulation will make the blood vessels on the surface of the nasal mucous membrane rupture and produce bleeding phenomenon. 3. Nasal tumor: nasal hemangioma is easy to bleed, and malignant tumors will be necrotic and bleeding phenomenon. 4. Systemic diseases: the more common ones are leukemia, coagulation factor deficiency or disorder, etc., which can cause nasal bleeding and other symptoms; abnormal liver and kidney function can also lead to coagulation disorder, causing nasal bleeding; hypertension fluctuation of elevated blood pressure can cause local blood vessel rupture and bleeding. 5. Nasal dryness, nasal dryness caused by environmental factors, or dry rhinitis, can appear symptoms of nosebleed. Nosebleed, need to ENT consultation, clear cause, follow the doctor’s instructions for treatment.