What is a postinfectious productive cough? when will the phlegm clear? i hate having to keep clearing my throat

Cough after cold: A postinfectious cough is one that happens after a normal cold and can last anywhere from 3-8 weeks. Once your doc makes sure nothing else is going on - like pneumonia or pertussis - then usually it's helping the symptoms. Rest assured, this usually goes away on its own. Antibiotics don't usually help, but certain inhalers can.