Nasal root with backflow of nasal mucus often refers to postnasal drip syndrome, which may be caused by allergic rhinitis, sinusitis and other factors. 1. Allergic rhinitis: the disease is related to heredity, contact with allergens and other factors, the patient’s nasal cavity will appear a large amount of secretion, manifested as a large amount of watery nasal mucus, nasal mucus can not be discharged in a timely manner, and there may be a reflux of the situation. 2. Sinusitis: the disease is an infectious disease caused by bacterial viruses and other pathogenic microorganisms, patients will have nasal congestion, a lot of pus, headache symptoms, pus may flow back to the throat, stimulate the mucous membrane tissue of the throat nausea, cough and other symptoms. There are many factors that lead to snot flowing backward from the root of the nasal cavity, you can actively go to the hospital, after clarifying the cause of the disease, follow the doctor’s instructions to standardize the treatment.