

Sinusitis refers to inflammation of the sinus cavities, which are moist, hollow spaces in the bones of the skull. There are four pairs of sinuses:
- Frontal sinuses
- Maxillary sinuses
- Ethmoid sinuses
- Sphenoid sinuses (not shown in illustration)
If the opening from a sinus cavity becomes plugged, the flow of mucus is blocked and pressure builds up, causing pain and inflammation.

Review Date:
4/13/2006
Reviewed By: A.D.A.M. Medical Illustration Team: Meredith Nienkamp, M.S.M.I., Dan Johnson, M.S.M.I., Lisa Higginbotham, M.S.M.I. Review also provided by VeriMed Healthcare Network.
Reviewed By: A.D.A.M. Medical Illustration Team: Meredith Nienkamp, M.S.M.I., Dan Johnson, M.S.M.I., Lisa Higginbotham, M.S.M.I. Review also provided by VeriMed Healthcare Network.


