How do you diagnose a sinus infection bacterial?

Sinus Infection: A ct scan of the sinuses can be done to diagnose sinus infection.

Generally clinically: Acute bacterial sinusitis has signs and symptoms which indicate its presence to an astute clinician, and does not usually require imaging studies unless complications are arising. If you have facial and periorbital pain and swelling, nasality of speech, pus from your nose, tenderness over the teeth or sinuses and have had a prior cold, allergy, trauma, etc., you have sinusitis. See a doctor.