1. Causes of Cough in Six-month-old Babies Cough in babies is a common symptom, but cough in six-month-old babies requires parents to pay great attention to it. Possible causes include colds, respiratory infections such as asthma, bronchitis, and pneumonia, and allergies. 2. How to relieve the cough of six-month-old babies. For coughs caused by different reasons, parents