How to tell the difference between allergies and sinusitis

Allergies and sinus infections are often mistaken for one another, but there are clues that can help you differentiate them. — TNS

Dear Mayo Clinic: I have had allergies since childhood, suffering during both the spring and fall seasons. This past month, however, I am experiencing more congestion and mucus, and I even have some facial pain. I'm beginning to wonder if my symptoms are really from allergies or if they may be caused by a sinus infection instead. How can I tell the difference?

Allergies and sinus infections are often mistaken for one another, but they are two separate conditions.