There are two types of cough medication -- expectorants and suppressants.
Expectorants
Expectorants help bring up mucous when you have congestion in your chest and it is not cleared with the cough.
These are the most useful when you have a wet, non productive cough.
Suppressants
If you have a productive cough, it is best not to take medication to suppress it.
Suppressants stifle the cough reflex and help you stop coughing.
Research on cough suppressants has shown that they do not work for many people. If you do choose to use a cough suppressant, they should generally only be used at night.
Learn more about Cough Medications and Kids.
Coughing is the body's reaction to a foreign object in the lungs, whether it is dust, mucous or another object. If you have chest congestion, coughing will help get it out of your lungs and help you heal more quickly. Suppressing this type of cough can lead to more serious illnesses like pneumonia.

