Pathophysiology

It is not clear yet, though there are theories suggesting the pathophysiology:

Chronic vasoconstriction leads to ischemia of the nasal mucosa, which predisposes to interstitial edema

Fatigue of the constrictor mechanisms occurs resulting in reactive hyperemia and congestion

Alteration in vasomotor tone results in increased vascular permeability and edema

The beta-adrenoreceptor activity may outlast the alpha effects leading to rebound vasodilatation