Newborns with phlegm sound is commonly caused by respiratory diseases, may also be a foreign body choking. 1. Respiratory infections: If a newborn is attacked by bacteria or viruses, it can cause pneumonia, bronchitis, pharyngitis and other respiratory infectious diseases, which can cause secretions in the respiratory tract, which can produce phlegm sounds when breathing, and can be accompanied by coughing, coughing up sputum, fever and other conditions. 2. Foreign body choking: If choking occurs during drinking water or milk, and if it gets stuck in the airway, it can cause temporary coughing and sputum sound, appropriate back patting or taking the Heimlich method to promote the expulsion of the foreign body, and if necessary, consult a doctor for treatment. If the phlegm sounds attack, it is recommended to take the baby to the pediatrician or respiratory department in time to avoid blindly self-medication.