The main reasons for wiping nasal snot with blood are as follows: 1. The mucous membrane of nasal cavity is eroded: the mucous membrane of nasal cavity is rich in tiny capillaries, of which there are arterial nature and venous nature. If the ruptured mucous membrane area contains venous blood vessels, the ruptured bleeding volume here is less and the bleeding speed is slower, the volume is small and slow, it will be shown as nasal mucus with blood, often when wiping nose or blowing nose, you will find nasal mucus with blood. 2. Therefore, if there is blood in the nasal cavity, it is important to have it. Therefore, if you have blood in your nose, you must go to the ENT department for a high-definition nasal endoscopy to identify whether it is a simple and common rupture of the nasal mucosa or a tumor growing in the nasal cavity, and you must not delay the condition because of taking it for granted.