Cough is always due to a Respiratory Tract condition, somewhere between the nose & depths of the lung.
We divide it into โUpperโ and โLowerโ Respiratory Tracts:
โข Upper Tract: nose, sinuses, throat, & trachea (windpipe)
โข Lower Tract: lungs
โข See Diagrams — Upper and Lower Respiratory Systems

For the clinician’s approach to diagnosing “Cough,” select either:
Acute Cough (lasting 2-3 weeks or less)
Chronic Cough (going on 4 weeks or more)