Acute and chronic rhinosinusitis (ARS and CRS) are common conditions with a significant impact on health-related quality of life and disease-related costs. ARS is predominantly of viral aetiology and self-limiting, while bacterial ARS is rare and overdiagnosed. CRS is a persistent inflammatory disease, categorised histopathologically by type of inflammation, with therapeutic strategies varying by severity and endotype. Recent advancements have improved outcomes for patients with severe CRS. This review finds that future research aims to refine biomarkers and personalise treatment for even more favorable outcomes.