A chronic cough (lasting more than eight weeks) has a few common underlying causes that can look quite similar from the outside, and reflux, postnasal drip, and asthma are three of the most frequent culprits, sometimes occurring together.
Clues that point toward reflux as the cause
A cough that's worse at night or shortly after lying down, occurring alongside a sour taste, throat clearing, or hoarseness, and one that doesn't respond to typical cough or allergy treatments, can all point toward silent reflux (LPR) as an underlying driver, even without classic heartburn present.
Clues that point toward postnasal drip
A cough accompanied by a sensation of mucus dripping down the back of the throat, nasal congestion, or a history of seasonal allergies points more toward postnasal drip, often related to allergies or chronic sinus issues, as the primary cause.
Clues that point toward asthma
A cough accompanied by wheezing, chest tightness, or shortness of breath, especially one that's triggered by exercise, cold air, or specific allergens, points more toward asthma, and a formal breathing test (spirometry) can help confirm this.
Why an accurate diagnosis matters here
Because these three causes require different treatments — acid suppression for reflux, antihistamines or nasal treatments for postnasal drip, inhalers for asthma — treating a chronic cough as the wrong one of these can mean months of ineffective treatment. If a chronic cough hasn't resolved with an initial treatment attempt, it's worth a broader evaluation considering all three possibilities rather than continuing down one path alone.
