LifestyleExplaining AllergiesTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoLifestyle04/18/2013April 18, 2013An allergy is an over-reaction by the body’s immune system against specific substances that it has misidentified as harmful. The immune system responds to substances that don’t actually present a risk to health.https://p.dw.com/p/18IMCAdvertisement