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What causes hay fever?

Hay fever is caused by an allergic reaction to particles that are breathed in and trapped by mucus inside the nose. During this allergic reaction, a natural chemical called histamine is released into the nose, mouth, throat and eyes, causing inflammation and swelling. Some examples of particles that may trigger this response include pollen, mold, dust mites and animal hair.

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Author: Dr Joanne Van der Velden PhD, BSc (Hons)
First answered: 18 Sep 2014
Last reviewed: 19 May 2018
Rating: 4.2 out of 5
Votes: 1432 (Click smiley face below to rate)
Category: Pink eye


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