Sinusitis is categorized by inflammation of the lining of the paranasal sinuses. As the nasal mucosa is instantaneously involved and as sinusitis infrequently occurs without concurrent rhinitis, rhinosinusitis is currently the preferred term for this condition. Acute sinusitis is a clinical diagnosis; thus, an understanding of its presentation is of paramount importance in differentiating this entity from allergic or vasomotor rhinitis and common upper respiratory infections. No precise clinical sign or symptom is sensitive or specific for acute sinusitis, so the overall clinical impression should be used to guide management. Chronic sinusitis is an inflammatory procedure that includes the paranasal sinuses and persists for 12 weeks or longer. The literature has reinforced that chronic sinusitis is nearly always accompanied by concurrent nasal airway inflammation and is frequently preceded by rhinitis symptoms; hence, the term chronic rhinosinusitis (CRS) has evolved to more accurately define this condition. Treatment of sinusitis, whether medical or surgical, is intended at decreasing inflammation and obstruction in the sinonasal passages. Antibiotics, even though frequently used in sinusitis, ought to not be managed unless there is suspicion of an acute bacterial infection.