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Immune System

Eosinophils

White blood cell subtype involved in allergic reactions and immune responses.

What is Eosinophils?

Eosinophils can increase with allergic conditions or certain infections. They are typically interpreted together with total leukocytes and the differential (other white cell types). Trends help distinguish a temporary change from a recurring pattern.

Why is Eosinophils relevant?

Eosinophils are a specific subset of white blood cells that mainly become active during allergic reactions — think asthma, hay fever, or food allergy — and during some parasitic infections. Elevated values are therefore a functional signal: they suggest the immune system is responding to a stimulus, not that something serious is necessarily wrong. For people with allergic complaints or a chronic inflammatory background, the marker can move with symptom patterns.

How to read Eosinophils in context

Eosinophils are almost never interpreted in isolation — the percentage and absolute count within the full leukocyte profile says more than a standalone value. A mild elevation without symptoms is often uninformative; alongside targeted symptoms (asthma, eczema, allergy, persistent cough) the marker gains meaning. Trends across measurements help distinguish a temporary response from a persistent pattern.

Eosinophils is one of 100+ biomarkers in the Optimize panel. Book a blood draw at any of 238+ partner labs in the Netherlands, or upload your existing results in the app.

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