What are allergies?
When your immune system is operating properly, it reacts to harmful things coming into your body by attacking and “killing” them. For example, it fights the germs that might otherwise cause you to get a cold or flu. However, sometimes your immune system makes a mistake and reacts negatively to things that are harmless to most people. These “things” that it mistakes as harmful become known as allergens (e.g., “triggers” that bring on allergy symptoms). For example, your immune system may decide that peanuts are allergens, and in response it produces antibodies to “fight” this allergen. In turn these antibodies create a chemical reaction in your body, including the releasing of histamines into your blood stream. As a result you may develop hives, feel your throat close, etc. Or perhaps you suffer from the common allergies related to certain pollens in your environment (e.g., “hayfever”). Your body may react to these pollen allergens with cold-like symptoms such as a runny nose, sneezing, and watery eyes.