why are some people allergic to certain things such as dust and pollen? how do most allergies occur?
The cause of allergies is unexplained by scientist although there are many fact as that may play a role in developing allergy. Some important factors are family history, age, environment, immunity etc. Although if a parent has allergy to pollen not necessarily the child of that parent have allergy to pollen, the child may have allergy to some other substance or may have no allergy at all.
Allergy occurs as a reaction when a substance enter our body which it considers as foreign. When these substance enter our body such as pollens certain chemicals known as histamines are released from our immune system which forms antibodies to kill the allergens creating a whole set of reaction to protect our body (simply meaning a reaction where immune system is overactive) which is described as allergy.