If a person has a runny nose when he lowers his head, it is due to the following reasons: 1. chronic rhinitis or deviated septum, when the patient has chronic rhinitis and deviated septum, there will be excessive secretion in the nasal cavity due to the infection factor, which leads to a runny nose and runny nose when he lowers his head due to gravity. 2. allergic factors, for example, when chronic allergic rhinitis, if he comes into contact with Allergic substances, such as dust mites, dust, fur and hair, will cause the nose to run when the head is lowered. However, this situation is likely to occur during the allergy-prone season, when people come into contact with allergy-causing factors. 3. When you have a cold, especially a wind-cold cold, the above symptoms will occur when the nasal cavity comes into contact with cold air.