The cough and phlegm symptoms of a 5-month-old child can be treated in the following ways: 1. Drink more plain water to replenish water and dilute phlegm, which can play a role in moistening the throat and relieving the cough and phlegm symptoms of the child. 2. Take Pediatric Lung Heat Cough and Asthma Oral Liquid, as the symptoms of cough and phlegm in children are usually caused by lung heat, and Pediatric Lung Heat Cough and Asthma Oral Liquid can clear lung heat, stop coughing and dissolve phlegm, which can relieve the symptoms. 3. 3.Treatment by taking snake bile and Chuanbei liquid can stop coughing and dissolve phlegm to relieve the symptoms of coughing and phlegm in children. 4.For coughing and phlegm caused by bacterial infection in the trachea and bronchi, antibiotics such as cefixime granules can be taken for treatment. 5.When the symptoms of coughing and phlegm are serious and accompanied by breathing difficulties, nebulization can be used to relieve the symptoms.