Colds and allergies may produce mucus that drains down the back of the throat (postnasal drainage). Home treatment may be all that is needed to provide relief if you have a productive cough and postnasal drainage but do not have other symptoms.
A productive cough in a person who smokes is often a sign of lung damage. For smokers, the most effective way to treat a cough is to stop smoking. A change in the cough or in the color or quantity of sputum may mean a bacterial lung infection.
A productive cough is a more serious when:
It produces sputum from the lungs (not postnasal drainage).
The sputum is rust-colored or contains bright red blood.