CT scan. This is a special kind of X-ray. It gives a detailed view of your nose and sinuses. Scans from different angles help show the exact place where the blockages are. They also serve as “maps” during surgery. In some cases, you may need more than one CT scan before your surgery.

Nasal endoscopy. This is a procedure that uses a slim, flexible tube with a fiberoptic light at the end. This is called an endoscope. The doctor puts the endoscope into your nose. This lets your doctor see the inside of your nose. He or she can also see your mucosa and the openings of your sinuses. If needed, your doctor can also take samples (biopsies) through the endoscope. These samples will be looked at by a lab.

Allergy tests. You may have these to find out what things you are allergic to.

Mucus sample (culture). The doctor may take these samples from your nose to check for infection.