Postnasal drip syndrome, postnasal drip syndrome, the standardized name is upper airway cough syndrome, mostly caused by chronic inflammation of the nasal cavity, sinuses, leading to secretion backflow to the throat caused by symptoms, common symptoms will involve the pharynx and nose. 1. Pharyngeal symptoms: The backflow of nasal secretions into the pharynx can cause throat discomfort. A paroxysmal or persistent cough, which may be accompanied by coughing up phlegm, often occurs during the attack. After the secretion flows into the pharynx, itchiness, foreign body sensation in the pharynx and frequent throat clearing are the clinical manifestations. 2. Nasal symptoms: chronic rhinitis, sinusitis and allergic rhinitis are common primary causes of post-nasal drip syndrome. During the onset of post-nasal drip syndrome, patients may experience symptoms such as yellow nasal discharge, nasal congestion, headache, frequent sneezing and itchy nose, and a large amount of clear nasal discharge. Patients with postnasal drip syndrome need to actively go to the ENT department of the hospital, diagnose the cause of the disease, and then follow the doctor’s instructions to standardize the treatment.