Can you tell me about non-productive cough. what could it be?

Causes of Cough.: Most common causes of cough include asthma, upper airway cough syndrome (post-nasal drip), reflux, chronic bronchitis (typically in smokers), medications (such as lisinopril). Your doctor should discuss your symptoms in detail to determine which of theses may be contributing to your cough. You may need pulmonary function test if asthma is a possible cause based on your symptoms.