Purpose of reviewRhinosinusitis affects more than 10% of the US population. It results in high health care expenditure as well as decreased productivity through lost days of school or work. This review includes recent findings in diagnostics and pathophysiology, as well as recent advances in treatment.Recent findingsParameters used in the diagnosis of rhinosinusitis include patient symptomatology, physical and endoscopic findings, computed tomography scan scores, and culture results. There has been poor correlation between patient symptoms and computed tomography scan scores, but middle meatal cultures have been shown to correlate well with ethmoid sinus cultures obtained from chronic rhinosinusitis patients. Chronic inflammation with a predominance of eosinophils and T lymphocytes in the tissues is being recognized as a hallmark of chronic rhinosinusitis, especially in patients with asthma or allergic rhinitis. Th2 cytokines are prominent in sinus tissues of patients with chronic rhinosinusitis and allergic rhinitis. While antibiotics are used with greater frequency in the treatment of acute and chronic rhinosinusitis, adjuvant therapies, such as intranasal steroids, might affect patient symptoms and curb disease recurrence.SummaryClinical symptoms are important in making the diagnosis of rhinosinusitis and should be supported by objective findings on nasal endoscopy and, if necessary, computed tomography scans. The mainstay of treatment remains antibiotics, with a potential role for decongestants and intranasal steroids. The presence of chronic inflammation with a Th2 cytokine predominance in sinus tissues should be kept in mind, especially in patients with coexistent morbidities such as allergic rhinitis and asthma.