The most common cause of cough and sputum in babies is increased secretions in the respiratory tract, and there are two reasons for increased respiratory secretions: one is increased production of secretions; the other is problems with the removal of secretions, both of which may lead to increased secretions, resulting in increased sputum and causing a cough. The most common cause of increased secretion is seen in infections, such as viral, bacterial, mycoplasma or tuberculosis infections, which can lead to damage to the airway epithelium of the respiratory tract, resulting in increased mucus secretion, which is one aspect. On the other hand, mucus clearance is impaired, mainly due to the destruction of respiratory ciliary epithelial cells, which can be caused by infections, as well as more specific ciliary dyskinesia syndromes or genetic problems, which can lead to impaired ciliary motility, resulting in problems with mucus clearance and causing cough and sputum.