Chronic rhinosinusitis (CRS) has a substantial effect on the patient’s quality of life. It has recently been accepted that CRS has multiple distinct components, e.g. infection and inflammation, which has led to changes in the therapeutic approach. In addition, it is no longer considered practical to manage CRS as a prolonged version of acute rhinosinusitis. A CRS diagnosis is based on the type and duration of symptoms, together with an objective finding of inflammation of the nasal mucosa or paranasal sinuses. Differences in treatment are based on the presence or absence of nasal polyps.