Whether the phlegm in the baby’s lungs will heal itself depends on the condition, as follows: a. It can heal itself: If the baby only has mild cough symptoms, can hear the phlegm sound in the throat, is in good spirits, eats, sleeps and plays normally, parents strengthen daily care, for example, usually give the baby some warm boiled water in appropriate amounts to dilute the phlegm and give a pat on the back, the phlegm will be easily expelled with the baby’s cough after dilution and shock. After the phlegm is diluted and shocked, it can be easily expelled with the baby’s coughing action. In addition, you can give your baby foods that have the effect of relieving cough and resolving phlegm, such as boiled water with rock sugar and snow pear or boiled water with white radish, which can promote self-healing. Second, not self-healing: If the baby has phlegm and coughs badly at the same time, and accompanied by symptoms such as fever or shortness of breath, it cannot heal itself. Parents should take the baby to the hospital for relevant examinations, such as blood routine, sputum culture, chest X-ray, etc., and give symptomatic medication treatment according to the examination results, so that the symptoms of phlegm in baby’s lungs can be cured.