Hi. my almost 4 year old had a viral infection a few weeks back and cant seem to shake the cough it has now become worse especialy at night. help pls?

It happens: Upper respiratory viruses often damage cells lining the airways that help move mucous within the lung. A cough is a natural reflex that helps move mucous from the deep areas of the lung where it has been trapped. This can persist for a month or so in some kids. Medications like Mucinex help thin secretions & work better than traditional cough meds that have antihistamines.