Sinusitis affects the paranasal sinuses.
These are air-filled cavities located within the bones of the skull surrounding the nose. They are lined with a mucous membrane that normally helps to filter and humidify air.
When this membrane becomes inflamed, it can block the sinuses' drainage openings, trapping mucus and causing pressure, pain, and other symptoms.
There are four main paranasal sinuses:
- Frontal sinuses: Located above the eyebrows.
- Maxillary sinuses: Located below the eyes.
- Ethmoid sinuses: Located between the eyes.
- Sphenoid sinuses: Located behind the nose.
Sinusitis can affect one or more of these sinuses, and the symptoms can vary depending on the location of the inflammation.
