Loading... Please wait...| A sinus headache is the result of a build-up of pressure within the sinuses of the skull. The sinuses are cavities or pockets within the bones of the skull. In addition to contributing to the strength and stability of the skull, the sinuses help to humidify and filter air. Inflammation due to any cause (most likely due to irritation or infection) can cause a buildup of fluid and increased pressure within the sinuses, giving rise to the typical symptoms of a sinus headache. |