What Is an Eosinophil Count?

An eosinophil is a kind of white blood cell whose job is to fight parasites in your body. Eosinophils play an important role in your body's inflammation response but, if the count is high for too long, the inflammation can damage body tissues.

Normal Ranges

• Anything more than 500 eosinophils per microliter of blood is abnormally high for adults, according to MayoClinic.com. However, different medical labs have different definitions of the "normal" range.

Tests

• A doctor runs a blood test to measure the eosinophil level of the bloodstream. In tissue, the count is measured by examining mucus or a skin biopsy from the relevant area of your body.

Diseases

• A high eosinophil count is a condition called "eosinophilia." In the developed world, the most common causes are allergies and asthma. In the developing world, the most common cause is parasitic infection.

Treatment

• Since eosinophilia is just a symptom of another disease, the first step in treatment is to diagnose the underlying cause. Allergy tests can determine what you are allergic to so that you can avoid those things. Stool tests can determine whether or not you need treatment for parasites like worms.