Why do humans have allergies?

Answer 1

Some examples of common antigens (things that cause allergic responses by your immune system) are: pollen, dust, molds of all types, some foods, and medicines.

Allergies result from an incorrect response by the immune system, when it attacks things that are not actually pathogens/invaders of the body.

Allergies are actually caused by our immune system. When we have an allergic reaction, it is because the substance confuses our immune system so that it over reacts to try to get rid of the foreign substance (pollen, pollutants, etc.) by creating excess fluids to wash away the antigen. Allergies sometimes cause other reactions that may even attack our tissues by mistake, instead of protecting us.

There is no real set pattern to what humans will have allergies to, but we can only be allergic to things we have been exposed to, and the longer we are exposed to something, the more likely we are to develop an allergy to it.
You can develop allergies that you didn't have before, but you can't catch them from someone else.

Answer 2

Different people are allergic to different things. Hay Fever is a general term for seasonal or envirmental allergices. When there is different types of plants growing, they produce pollen and other substances that people have allergies to. Because a specific allegen is not or cannot identified the person is said to have Hay Fever.

Answer 3

Causes of allergies include predisposition due to genetics, insufficient immune system, lack of early childhood exposure to infectious agents, and numerous environmental factors. Food allergies are the body's adverse reactions to foreign proteins.

Answer 4

Allergies are mostly related to repeated exposure -- to any substance.

Answer 5

some people get allergies while others do not, maybe passed down through your genes.

Answer 6

they have to get aids first

Answer 7

paintball :D