Yellow nasal discharge is mostly seen in the late stage of cold or acute and chronic sinusitis. If yellow nasal discharge becomes white nasal discharge in the late stage of cold, it is considered to be accompanied by allergic factors, which can be treated with additional anti-allergic drugs, such as levocetirizine, etc., to facilitate recovery from cold. When yellow snot becomes white snot in chronic sinusitis, it means that sinusitis is in the process of improvement, that is, the treatment given to sinusitis is effective, and it is necessary to continue with the medication, generally needing oral antibiotics, such as clarithromycin, nasal spray tretinoin, physiological seawater, etc., to reduce the edema of the nasal mucosa and facilitate the discharge of snot from the sinus opening. The general course of treatment for sinusitis is two weeks, and most sinusitis will be effectively controlled after the above treatment. Therefore, there is no need to worry too much about the phenomenon of yellow nasal mucus turning into white nasal mucus, and treatment can be carried out.