Eosinophils
White blood cells that respond to allergies and parasitic infections.
What is it
Eosinophils participate in allergic responses and defend against parasitic infections.
Why it's measured
Eosinophil counts have been used in evaluating allergic conditions and parasitic infections in research and clinical practice.
Reference range
Standard laboratory reference
1 – 4% of WBC
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with allergic conditions, asthma, parasitic infections, and certain medications in research literature.
Lower
Generally not clinically concerning.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Part of standard CBC with differential.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.