Nasal Congestion

Nasal Congestion: Swelling Mechanism

Nasal congestion is the feeling of difficult nasal breathing that occurs not because of mucus buildup (as in runny nose), but due to swelling of the mucous membrane that lines the nasal passages. Often the swelling, rather than the amount of secretions, causes the greatest discomfort, disrupting sleep and overall well‑being.

What happens in the nasal vessels?

The nasal mucosa has a unique structure. Beneath its surface are the so‑called cavernous bodies – lobular formations penetrated by a dense network of blood vessels. These structures can quickly change their volume, regulating blood filling. In response to inflammation (caused by viruses or allergens) or other irritants, the vessels dilate sharply. This leads to a strong blood influx, causing the cavernous bodies to swell and enlarge significantly, mechanically blocking the nasal passages. This is the mechanism of congestion.

Main causes of congestion

• Infections: URIs, acute or chronic sinusitis (inflammation of the paranasal sinuses).
• Allergies: Seasonal and perennial allergic rhinitis.
• Structural anomalies: Deviated nasal septum, nasal polyps.
• Adenoids: Enlargement of the nasopharyngeal tonsil is the most common cause of chronic congestion in children. More details on the page "Nasal Congestion in Children".
• Medication‑induced rhinitis: “Rebound” congestion that occurs with prolonged (more than 5–7 days) use of vasoconstrictive drops.

Chronic nasal congestion forces a person to breathe through the mouth, which can lead to snoring, sleep apnea and frequent throat infections.