What is "sinusitis"?

What is "sinusitis"?

Harold Kaiser (Practicing Allergist and Clinical Professor of Medicine, University of Minnesota Medical School) gives expert video advice on: What causes allergies?; What happens in my body when I have an allergic reaction?; Are allergies becoming more common? and more...

Sinusitis is inflammation of the sinuses. The sinuses are the cavities behind our cheeks and behind our forehead which help to make up the skull. They're lined with mucus secreting membranes and when these membranes become infected or inflamed, there's congestion and this congestion can lead to a block which leads to sinusitis - inflammation of the sinuses.