Why is isnofilia in medical terms?

Question

Is it checking blood for respiratory infection, why it is done

Answer 1

Eosinophils are a type of white blood corpuscles normally upto ten in hundred white cells,increase in numbers in immunological response of body like allergy.Their increase in blood suggests that an allergen is in the body and body is reacting the normal way.Rarely there can be a very great increase in eosinophils like in Eosinophilic leukemia.

Answer 2

Eosinophils are increased in the blood in allergic conditions such as asthma and allergic skin conditions. They are also increased due to infestation by worms and other parasites.