Nasal reflux, old phlegm, i.e. postnasal drip syndrome, mostly occurs in chronic rhinitis, sinusitis, allergic rhinitis and other diseases, can be treated accordingly for different diseases, such as oral medication, nasal spray, surgery and so on. 1. Chronic rhinitis: hormonal nasal sprays such as budesonide are commonly used to control nasal inflammation. Or vasoconstrictor such as ephedrine nasal spray to reduce nasal congestion. Can be combined with oral Nasal Abyss Tongjiao granules to relieve nasal mucosa inflammation. If conservative drug treatment is ineffective, surgical treatment can be considered, including partial inferior turbinate resection, low temperature plasma inferior turbinate ablation. 2. Sinusitis: If bacterial infection exists, antibiotics such as cefradine and clarithromycin can be taken orally to control the infection and reduce nasal secretion. Eucalyptus-pinocampus enteric capsule can also be taken to promote the discharge of secretions. Surgery can be considered if conservative treatment is not effective. 3. Allergic rhinitis: Go to the hospital to find out the allergens and keep away from allergens in daily life. During acute attack, oral cetirizine can be taken to control allergic symptoms. Combined with budesonide nasal spray to control inflammation and reduce nasal secretion to stimulate the throat. Patients can also take watermelon cream tablets for symptomatic treatment, but the treatment of the cause is the key, it is recommended to go to the hospital to do a systematic examination to clarify the diagnosis, and follow the doctor’s instructions to use the above drugs and standardized treatment.