A 40-day-old baby coughing twice a day is mostly normal if the baby is in good general condition with no other discomforts. If there is shortness of breath, foamy mouth, fever, anorexia, etc., it suggests that there may be respiratory infections and timely hospitalization is recommended. When infants take milk too fast, it is too late to swallow and may irritate the pharynx to cough. In addition, the indoor temperature is too low, dust stimulation, etc., can also cause coughing, at this time the baby’s mental condition is good, sleep is stable, no foamy mouth, no crying and other discomforts, is a normal phenomenon, no need for special medication. Infants in addition to coughing, accompanied by foamy mouth, shortness of breath, anorexia, and even fever, lethargy and other manifestations, more suggestive of the presence of respiratory infections, such as bronchitis, bronchopneumonia, etc., should be timely hospitalization, improve the blood routine, chest X-ray and other related tests, a clear diagnosis. 40 days of infants are coughing twice a day, parents should closely observe the baby’s state, if necessary, timely pediatric consultation, clear cause, take targeted treatment.