Allergies? A cold? Acid reflux? No matter what the cause, there’s a simple reason behind all your hacking: “A cough is a protective mechanism to clear your airway,” explains Jonathan Parsons, MD, Director of the Cough Clinic at the Ohio State University Wexner Medical Center.

While it’s impossible to always pinpoint a cough by how it sounds, there are some key differences to give you clues as to what’s going on. Here’s how to tell what that cough really means.