The nose belongs to the upper respiratory tract, if there is an itchy nose, runny nose, certainly the upper respiratory tract is stimulated. Specifically as follows: 1, the common cold, the common cold due to external evil stimulation triggered by the nose reaction, there will be sneezing, runny nose, because there is an external evil, direct relief of the surface, the external evil can be evacuated; 2, nose allergies will also appear sneezing, runny nose, not necessarily have an external sense of the Western medical examination does not necessarily have a virus, but only to the outside world sensitive to the external environment, is due to the patient to meet the allergens, the allergens are not necessarily all pathogens The allergens are not always germs, there may be artemisia, paint, so you need anti-allergy treatment, Chinese medicine to ease the wind, relief of the surface, consolidate the guard.