Suddenly flow a lot of nosebleeds, the root cause is due to the rupture of nasal blood vessels, may be associated with rhinitis – sinusitis, nasal tumors, trauma, blood disorders and other causes. 1. Rhinitis, sinusitis: due to the inflammatory stimulation of the nasal cavity and sinuses, it will lead to dryness or edema of the nasal mucosa, if you have the habit of digging your nose with your fingers, it is easy to lead to the erosion of the nasal mucosa, and then you will have a sudden nosebleed. 2. Nasal tumor: including nasopharyngeal fibrovascular tumor or nasopharyngeal malignant tumor, if the surface of the swelling erosion, blood vessel rupture, it is easy to bleed. According to the examination of nasal endoscopy, sinus CT, etc., it is necessary to clarify the cause and then target treatment. 3. Trauma: If the mucous membrane inside the nasal cavity is damaged due to impact, it can lead to blood vessel rupture and sudden bleeding. Finger pressure can be used to pinch the nose, pressure to stop bleeding, if it can not be relieved, then you need to go to the hospital in time. 4. Blood diseases: such as leukemia, thrombocytopenia and other conditions, coagulation function is abnormal, which will lead to sudden massive bleeding and difficult to stop the nose. If the patient’s nose suddenly appeared, it should be taken seriously, to seek medical treatment in time, identify the cause of the disease, timely treatment, so as not to delay the condition.