Nosebleed, first hang up the ENT department to stop bleeding and deal with the lesion urgently, and then check the differential diagnosis according to the common diseases that may cause this symptom respectively, such as cardiovascular internal medicine, hematology and so on. The common causes of nosebleed are cerebrovascular disease, blood disease, nasal disease and so on. 1. Cerebrovascular disease: common hypertension, cerebrovascular malformation, vascular sclerosis, etc., in emotional excitement or exertion can induce cerebral blood vessel rupture, may cause the involvement of the surrounding organs to appear corresponding symptoms, such as headache, dizziness, nosebleed and other symptoms. Nosebleeds caused by this condition can be listed in the cerebrovascular department or neurology. 2. Blood diseases: when suffering from blood diseases such as hemophilia, leukemia, aplastic anemia, etc., the abnormalities of platelets or coagulation factors can cause nosebleeds, and this situation can be listed in hematology. 3. Nasal diseases: bleeding caused by nasal diseases such as rhinitis, atrophic rhinitis, deviated nasal septum, etc., you can see the ear, nose and throat department. Nosebleeds need to go to the hospital in time for examination, after clarifying the specific causes, targeted standardized treatment, so as not to delay the condition.