Allergies cause a stuffy nose primarily by triggering inflammation and swelling in the mucous membranes lining your nasal passages and sinuses, which blocks drainage and leads to congestion.
Here's a breakdown of the process:
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Allergen Exposure: When you encounter an allergen (like pollen, dust mites, or pet dander), your immune system mistakenly identifies it as a threat.
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Histamine Release: This triggers the release of histamine and other chemicals. Histamine's effects cause several symptoms, including:
- Increased Mucus Production: The nasal passages start producing more mucus.
- Inflammation and Swelling: The tissues lining your nasal passages become inflamed and swollen.
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Sinus Blockage: The swelling in the mucous membranes obstructs the sinus openings.
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Congestion: Because the sinuses can't drain properly, mucus and air become trapped, leading to the feeling of congestion, pressure, and a stuffy nose. This trapped mucus can also create a breeding ground for bacteria, sometimes leading to a sinus infection.
In summary, the allergic reaction causes inflammation that blocks sinus drainage, leading to the accumulation of mucus and the sensation of a stuffy nose.
