What is eosinophilia?
Eosinophilia is the state of having an excessive percentage of eosinophils, which are a type of white blood cell. There are several types of white blood cells which may be tested by a blood test. Usually, people have 0-5% of their total white blood cells as eosinophils. Some labs make the cut-off 3%, and a few make it as high as 7%. Therefore, if your total percentage of eosinophils exceeds 5% to 7%, you have borderline eosinophilia or actual, progressing eosinophilia, and may need to be re-tested, require treatment or investigation as to what is causing the eosinophilia.