Nasal endoscopy
A thin, flexible tube (endoscope) with a fiber-optic light inserted through your nose allows your doctor to see the inside of your sinuses. This also is known as rhinoscopy.Imaging studies
Images taken using a CT scan or MRI can show details of your sinuses and nasal area. These might pinpoint a deep inflammation or physical obstruction that's difficult to detect using an endoscope.Nasal and sinus cultures
Cultures are generally unnecessary for diagnosing chronic sinusitis. However, when the condition fails to respond to treatment or is worsening, tissue cultures might help determine the cause, such as bacteria or fungi.An allergy test
If your doctor suspects that the condition might be triggered by allergies, he or she might recommend an allergy skin test. A skin test is safe and quick and can help pinpoint the allergen that's responsible for your nasal flare-ups.
