Pathophysiology of Nasal Congestion in Rhinitis
Nasal congestion in rhinitis results from mucosal inflammation causing venous engorgement, tissue edema, and increased secretions, with autonomic nervous system dysregulation further modulating vascular tone and sensory perception. 1
Vascular and Inflammatory Mechanisms
The nasal mucosa is extremely vascular, and congestion develops through multiple interrelated inflammatory pathways 2, 3:
Venous engorgement occurs as the primary mechanism of obstruction, driven by inflammatory mediators that cause blood vessel dilation and increased blood flow to the nasal mucosa 1
Tissue edema and swelling develop as inflammatory cells (activated eosinophils and TH2 cells) infiltrate the nasal mucosa in response to chemoattractant factors including IL-5, cysteinyl leukotrienes, and eotaxin 4
Increased nasal secretions contribute to the sensation of congestion and impaired airflow 1
Biphasic Allergic Response
In allergic rhinitis specifically, congestion manifests through two distinct phases 4:
Early phase response (immediate): Chemical mediators including histamine, prostaglandins, and leukotrienes trigger sensory nerve terminals and blood vessels, causing rapid onset of sneezing, rhinorrhea, and nasal congestion 4
Late phase response (6-10 hours post-exposure): Sustained inflammatory cell infiltration causes prolonged mucosal edema and congestion, with mucosal remodeling occurring after extended periods 4
Autonomic Nervous System Dysregulation
The autonomic nervous system plays a critical role in modulating nasal vascular tone 2, 3:
Parasympathetic stimulation increases nasal cavity resistance and promotes nasal gland secretion, worsening congestion 2, 3
Sympathetic stimulation causes vasoconstriction and decreases nasal cavity resistance 2, 3
Nonadrenergic noncholinergic system releases neuropeptides like substance P, though their exact contribution to clinical symptoms remains unclear 3
Altered Sensory Perception
Beyond physical obstruction, inflammation modifies sensory nerve properties 1:
Changes in sensory afferent expression of peptides and receptors can create a subjective feeling of congestion even without complete physical blockage 1
This neurogenic mechanism is activated after liberation of substance P and other neuropeptides 4
Common Pitfalls
The sensation of nasal congestion does not always correlate directly with objective airflow measurements—patients may feel congested due to altered sensory perception even when physical obstruction is minimal 1. This explains why some patients report persistent congestion despite treatment that reduces mucosal inflammation.