How can i tell if my throat clearing (phlegm) is due to reflux or post nasal drip? i have gerd but i take a ppi & i thought it was controlled.

It can be tough.: Your conundrum is a common one. Throat clearing can be a common sign of various conditions, including GERD but also allergies and common viral infections. It's difficult to tell the difference at times, but if your GERD is and has been well controlled, then perhaps you should consider alternatives. Other viral symptoms or nasal/eye itching could point you toward a cold or allergies, respectively.