Your doctor will feel for tenderness in your nose and face and look inside your nose.
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 or MRI can show details of your sinuses and nasal area. While not recommended for uncomplicated acute sinusitis, imaging studies might help identify abnormalities or suspected complications.
- Nasal and sinus cultures. Laboratory tests are generally unnecessary for diagnosing acute sinusitis. However, when the condition fails to respond to treatment or is worsening, tissue cultures might help determine 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 responsible for your nasal flare-ups.