Nasal congestion, which may be described as fullness, obstruction, reduced airflow, or being "stuffed up," is a commonly encountered symptom in clinical practice. Systematic study of congestion has largely considered it as a component of a disease state. Conditions associated with congestion include nasal polyposis, obstructive sleep apnea, and anatomic variation; however, most information on the burden of congestion comes from studies of allergic rhinitis and rhinosinusitis, diseases of which congestion is the major symptom. Congestion can be caused by other rhinologic conditions, such as non-allergic rhinitis, viral or bacterial rhinitis, and vasomotor rhinitis. Allergic rhinitis affects as much as one quarter of the population worldwide and imposes a significant economic burden. Additionally, allergic rhinitis significantly impairs quality of life; congestion causes allergic rhinitis sufferers decreased daytime productivity at work or school and reduces night-time sleep time and quality. Annually, rhinosinusitis affects tens of millions of Americans and leads to approximately $6 billion in overall health care expenditures; it has been found to be one of the most costly physical conditions for US employers. Given the high prevalence and significant social and economic burden of nasal congestion, this symptom should be a key consideration in treating patients with rhinologic disease, and there continues to be a significant unmet medical need for effective treatment options for this condition.