Diagnosis

Your doctor may ask about your symptoms. He or she may feel for tenderness in your nose and face and look inside your nose. Your doctor can usually make the diagnosis based on the physical exam.

Other methods that might be used to diagnose acute sinusitis and rule out other conditions include:

• Nasal endoscopy. A thin, flexible tube (endoscope) with a fiber-optic light inserted through your nose allows your doctor to visually inspect the inside of your sinuses.
• Imaging studies. A CT scan shows details of your sinuses and nasal area. It's not usually recommended for uncomplicated acute sinusitis, but imaging studies might help find abnormalities or suspected complications.
• Nasal and sinus samples. Lab tests aren't generally necessary for diagnosing acute sinusitis. However, when the condition fails to respond to treatment or is worsening, tissue samples (cultures) from your nose or sinuses might help find the cause, such as a bacterial infection.
• Allergy testing. If your doctor suspects that allergies have triggered your acute sinusitis, he or she will recommend an allergy skin test. A skin test is safe and quick and can help pinpoint the allergen that's causing your nasal flare-ups.