Nasal Congestion

A blocked, stuffy nose caused by swollen nasal lining and excess mucus — most often from viral colds, allergic rhinitis, or sinusitis. Most cases resolve on their own, and the biggest pitfalls are overusing decongestant sprays (which cause rebound congestion) and mistaking a structural problem for an allergy.

Evidence synthesis: Isotonic saline irrigation has solid evidence for reducing congestion and symptom duration in both colds and chronic rhinosinusitis. For allergic rhinitis, intranasal corticosteroids are the most effective single treatment across dozens of trials, outperforming antihistamines for congestion specifically. Quercetin has small randomised trials suggesting reduced allergic symptoms including congestion, but study quality is modest and doses used were high. Topical decongestants (oxymetazoline) are highly effective for 3 days but cause rhinitis medicamentosa — rebound congestion — with longer use, a well-documented trap. Persistent unilateral congestion raises concern for structural causes (deviated septum, polyps) or, rarely, tumours.