Why are people allergic to things?

Updated February 21, 2017 | Factmonster Staff

“Allergens” are things, such as pollens from trees or hair from animals, that trick our bodies into thinking we are fighting a cold or virus. These allergens make people who are prone to allergies have symptoms like runny noses, watery eyes and coughs. Not everyone, however, is prone to allergies. But if you are, allergies can be a pain in the neck. Who wants to walk around always feeling like they have a cold?

Sources +