Newborns with phlegmatic tones may have a lot of pharyngeal mucosal secretions, congenital laryngeal cartilage dysplasia, upper respiratory tract infections and so on. 1. More secretions: If the indoor air is dry and the nasopharyngeal mucous membrane has more secretions, there may be phlegm in the pharynx and phlegm sounds. 2. Laryngeal cartilage dysplasia: most of the laryngeal cartilage dysplasia is congenital, and there is wheezing sound. After birth, timely supplementation of vitamin D and promotion of calcium absorption may improve the situation. 3. Upper respiratory tract infections: If you get cold or infected by family members, resulting in respiratory tract infections, nasopharyngeal mucosal secretions will also increase phlegm sounds. Newborns with phlegm sounds may also have other causes, such as pneumonia, etc. It is recommended to go to the hospital in a timely manner, improve the examination to determine the cause of the disease, and then give targeted treatment or therapy. All of the above medications should be used under the supervision of a doctor.