Eosinophil count in serum/plasma (absolute)

Why This Test Might Be Ordered

Your healthcare provider may order this test to diagnose or monitor conditions such as allergies, asthma, parasitic infections, certain cancers (like leukemia), or autoimmune diseases. It can also help assess reactions to medications or identify unexplained symptoms like chronic fatigue or skin rashes.

What to Expect Before the Test

No special preparation is needed for this test. You’ll typically have a small needle inserted into a vein (usually in your arm) to draw blood. The process is quick and usually painless. If you’re on blood thinners, let your provider know before the test.

What the Test Results Mean

Elevated eosinophil counts may suggest allergies, infections, or inflammatory conditions. Lower-than-normal levels might indicate certain immune disorders or stress. Your provider will interpret results in the context of your overall health and symptoms.

Common Conditions Monitored

Eosinophil counts are often checked in patients with suspected allergic reactions, parasitic infections, or conditions like eosinophilic esophagitis, eosinophilic granulomatosis with polyangiitis, or chronic eosinophilic leukemia.