Children’s sudden sore throat and cough with phlegm and low fever may be caused by acute upper respiratory tract infection, allergic reaction, pneumonia, etc. Specific treatment programs need to be formulated in conjunction with the cause of the disease. 1. Acute upper respiratory tract infection: children are susceptible to infection by pathogenic microorganisms, resulting in acute upper respiratory tract infection, inflammation of the pharynx, making the respiratory mucosa irritation, showing a sudden sore throat, cough, phlegm, low fever, etc., you can use ibuprofen suspension coagulant, acetaminophen, pediatric cough syrup and other medications under the advice of a doctor. 2. Allergic reaction: If children belong to allergy-prone body, daily by dust, smoke and other allergens stimulation, making children suddenly appear sore throat, coughing, in serious cases, with low fever, coughing phlegm symptoms, can be in the doctor’s advice and guidance, choose loratadine syrup, cetirizine tablets and other drugs to treat, to pay attention to avoid contact with allergens. 3. Pneumonia: Pneumonia in children is usually caused by inflammation of the lungs due to bacterial or viral infections, and usually results in coughing, sore throat, low-grade fever, and difficulty in breathing, etc. Under the advice of the doctor, antibacterial and antiviral medications should be chosen for symptomatic treatment. Provide children with a safe and comfortable living environment on a daily basis. If children suddenly have a sore throat and cough with phlegm and low fever can not be relieved, they should go to the hospital in time for examination and symptomatic treatment to avoid delaying the children’s condition. The above drugs are used under the guidance of a doctor.