Coughing and phlegm in the airway in this age group is usually caused by a respiratory infection, and the inflammation will lead to an increase in secretions in the airway, which may result in a whistling sound. You need to treat your child with medication to reduce phlegm and relieve cough, and you can choose Ambroxol to give your child nebulized inhalation. In addition, the main thing is to clarify whether the child is caused by infectious or non-infectious factors. If it is caused by infectious factors, we need to see whether it is caused by bacterial infection or viral infection, so the routine blood test is necessary. Based on the results of the blood test, it will be determined whether antibiotics are needed. In addition, if it is caused by non-infectious factors, then the chronic inflammatory response of the airway should be considered, and this situation needs to be given to the child nebulized inhalation. Nebulized inhalation can significantly reduce airway hyperresponsiveness and inhibit the inflammatory response of the airway.