Nasal and sinus complaints are among the most common reasons for visits to primary care clinicians, otolaryngologists, and allergists. Although some clinicians consider nasal obstruction to imply a blockage within the nasal cavity, nasal obstruction is most commonly defined as a patient symptom manifested as a sensation of insufficient airflow through the nose . Nasal obstruction may be the cardinal presenting symptom of many common disease processes, such as rhinitis, sinusitis, septal deviation, adenoid hypertrophy, and nasal trauma.
This topic will focus on the clinical manifestations, evaluation, and treatment of nasal obstruction in adults. The structural causes of nasal symptoms and other specific diseases associated with nasal obstruction are discussed separately. (See "Etiologies of nasal symptoms: An overview" and "Cancer of the nasal vestibule" and "Tumors of the nasal cavity" and "Congenital anomalies of the nose" and "Nasal trauma and fractures in children" and "An overview of rhinitis" and "Acute sinusitis and rhinosinusitis in adults: Clinical manifestations and diagnosis" and "Clinical manifestations, pathophysiology, and diagnosis of chronic rhinosinusitis" and "Acute sinusitis and rhinosinusitis in adults: Treatment".)
The risk factors for nasal obstruction relate directly to the underlying etiology. Several common risk factors for nasal obstruction include a history of atopy, recurrent sinusitis, nasal trauma, nasal surgery, having household pets, exposure to poor air quality, and a family history of nasal polyposis [2-4]. Nasal obstruction commonly accompanies many other comorbid conditions including asthma and obstructive sleep apnea .
The pathogenesis of nasal obstruction may be related to abnormalities occurring with any of the anatomic structures and functions within the nose. Normal nasal anatomy and function are discussed elsewhere. (See "Etiologies of nasal symptoms: An overview", section on 'Nasal anatomy and function'.)
Nasal obstruction may be generally divided into mucosal and structural causes (table 1). The nasal mucosa is a complex tissue that is subject to local and systemic insults, leading to nasal obstruction. Examples of mucosal causes of nasal obstruction include bacterial sinusitis, nasal polyps, and soft tissue turbinate hypertrophy due to allergic rhinitis. There is also a normal, cyclical pattern of turbinate mucosal swelling, which alternates between sides of the nasal septum at intervals of two to five hours, referred to as the nasal cycle . Disruption of the nasal cycle can contribute to nasal obstruction.