After acute rhinitis or allergic rhinitis, the mucous membrane of the nasal cavity becomes congested and dry, which causes the rupture of capillaries when blowing the nose, resulting in nasal discharge with blood, but the amount of bleeding is small and can be relieved as the rhinitis symptoms improve. If there is still no relief, further nasopharyngoscopy should be performed to observe whether there are new organisms formed in the nasal cavity and nasopharynx; sinus CT examination should also be performed to exclude sinus abnormalities; corresponding hematological examination should also be done to exclude anemia, acute infectious diseases and blood diseases.