Whether a two-month-old cough with phlegm will heal on its own depends on the severity of the condition, the cause and the individual’s constitution, and cannot be generalized. If the cough is caused by a bacterial infection, a clear-colored sputum is a sign of self-healing, and it will take about 7 days to heal. If the cough is caused by a viral cold, the sputum is yellow. There is no specific medicine for viral cold, and it usually cures itself in 10 days. If the condition does not improve after 10 days, the condition is considered to deteriorate further and repeated cough with sputum can cause neonatal pneumonia. At this time, it will be accompanied by fever, lack of energy, difficulty in breathing and other symptoms, the symptoms are more urgent and serious, and the possibility of self-healing is smaller, so we recommend hospitalization. If the cough with phlegm is caused by allergic rhinitis, it is less likely to heal on its own and prompt treatment is recommended. Therefore, when a two-month-old baby has a cough with phlegm, parents are advised to take their child to the pediatric respiratory department of a regular hospital in time for examination to clarify the cause and then treat it symptomatically.