Sinusitis

Sinusitis refers to inflammation of the sinuses. The sinuses are spaces within the bones of the face and connect to the nasal passages. They produce mucous, which drains into the nose and helps to trap inhaled particles, and they help to humidify the air that is breathed in. Sinus inflammation is most commonly due to infection (bacterial or viral), irritation (e.g. chlorine from swimming pools, or cigarette smoke) or allergy (hay fever).