Skip to content Priority Health

Priority Health - What is a sinus infection?

What is a sinus infection?


A sinus infection is an inflammation of the mucous membranes that line the inside of the nose and sinuses. Sinuses are hollow spaces, or cavities, located around your eyes, cheeks, and nose.

When a mucous membrane becomes inflamed, it swells, blocking the drainage of fluid from the sinuses into the nose and throat, which causes pressure and pain in the sinuses.