Postnasal drip syndrome is often characterized by coughing, phlegm, foreign body sensation in the throat, and throat itching due to the backflow of nasal secretions into the nasopharynx. Postnasal drip syndrome is associated with a variety of nasal diseases, such as chronic rhinitis, chronic sinusitis, and deviated septum. Intranasal secretions from inflamed areas of the nose and sinuses flow backward into the nasopharynx, oropharynx, etc., thereby irritating the area and causing discomfort. The most common symptoms are coughing, coughing up phlegm, etc. As the mucus adheres to the back wall of the pharynx, foreign body sensation in the pharynx, burning sensation, and itching in the throat can also occur. If postnasal drip syndrome is caused by chronic rhinitis, chronic sinusitis and other diseases, it can also be accompanied by regular coughing at night, choking and other symptoms. Specific symptoms have some individual differences, discomfort, it is recommended to consult a doctor in a timely manner, diagnosed by a professional doctor.