A cough is a bodily reaction that allows the lungs and upper airways to remove foreign material and mucus. Coughing is a natural process that’s often harmless, but as it’s a symptom rather than a disease, it can be indicative of a more serious lung condition.
There are two different types of coughs—productive coughs, in which phlegm or mucus is produced, and non-productive coughs, which are dry and produce no mucus.