What physiological change occurs during an allergic reaction?

During an allergic reaction, the body often encounters an allergen, which triggers the immune system to respond. This response includes the release of histamines and other chemicals that lead to various physiological changes. One of the most notable effects of this immune response is increased mucus production.

Mucus plays a vital role in protecting the respiratory system, as it helps trap allergens, pathogens, and irritants. The increase in mucus production can lead to symptoms such as nasal congestion, sneezing, and coughing, which are common in allergic reactions. This phenomenon is especially pronounced in reactions such as hay fever or allergic rhinitis, where the nasal passages become inflamed and produce excess mucus.

Understanding this mechanism is crucial because it highlights how the body attempts to defend itself against perceived threats, even if those threats are harmless allergens.