There are many harmful effects of frequent digging of the nostrils, such as nasal hair damage, nasal mucous membrane damage bleeding, secondary infection. 1. Nasal hair damage: Nasal hair is the first line of defense of the nasal cavity, often digging the nostrils will lead to more nasal hair shedding, resulting in the nostrils lose the protection of the nasal hairs, it is easier to let the harmful substances in the air into the respiratory tract. 2. Nasal mucous membrane bleeding: often digging the nostrils will damage the mucous membrane in the nasal cavity, the nasal cavity has a lot of capillaries, so it is easy to lead to nasal mucous membrane damage, resulting in bleeding phenomenon. 3. secondary infection: often digging the nostrils may lead to nail or hand pathogens, through the nasal mucosa damage into the body and thus cause infection phenomenon, nasal infection can cause serious intracranial infection, life-threatening. Frequent digging of the nostrils has many harmful effects, daily need to avoid frequent digging of the nostrils, if there are symptoms of discomfort, should go to the hospital in a timely manner to improve the examination, to identify the cause of the standardized treatment.