A blocked nose, or nasal congestion, is most commonly caused by swelling of the tissues lining the nasal passages. This swelling is a result of inflamed blood vessels. Several factors can trigger this inflammation.
Common Causes of a Blocked Nose
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Infections: The common cold, the flu (influenza), and sinusitis (a sinus infection) are frequent culprits. These infections cause inflammation and irritation, leading to swelling and mucus production, blocking the nasal passages. [Source: Mount Sinai, Mayo Clinic, Healthline, Top Doctors]
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Allergies: Seasonal allergies (hay fever) or allergies to substances like pet dander, dust mites, or pollen are major contributors. The body's allergic reaction causes inflammation and increased mucus production, resulting in a stuffy nose. [Source: Mount Sinai, Mayo Clinic, MedlinePlus, Vicks]
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Irritants: Exposure to irritants such as smoke, perfume, paint fumes, and even certain foods or drinks (like alcohol) can irritate the nasal lining, causing inflammation and congestion. [Source: NHS]
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Nasal Polyps: These noncancerous growths in the nasal passages can obstruct airflow, leading to a blocked nose. They can cause nasal congestion, runny nose, and sinus pressure. [Source: Johns Hopkins Medicine]
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Other Factors: Changes in weather (temperature or humidity), exercise, and even overuse of certain over-the-counter nasal sprays can also contribute to nasal congestion. [Source: NHS, MedlinePlus]
Understanding the Mechanism
Many believe excessive thick mucus is the primary cause, but it's primarily the swelling of the nasal lining tissues due to inflamed blood vessels that causes the blockage. [Source: Vicks]
