Hay fever is an allergic reaction to pollen and dust. It can be seasonal, t

Hay fever, also known as allergic rhinitis, is the fifth most common allerg

The immune system reacts against foreign substances that enter the human bo

An allergy is a reaction by the human immune system to anything that is not

The role of the body's immune system is to fight bacteria and other disease

Allergies are hypersensitive immune responses to foreign substances like po