What Causes Nasal Congestion? Nasal congestion occurs when the nasal passages become inflamed or swollen, restricting airflow and leading to that familiar feeling of a nasal congestion stuffy nose. Common causes include: Allergies: Seasonal or environmental allergens like pollen or pet dander can trigger inflammation. Infections: Viral infections like the cold or flu often ca... https://pacificviewent.com/dizziness-vertigo/