Eosinophil count in whole blood (absolute)
This test measures the number of eosinophils, a type of white blood cell, in your blood. Eosinophils help fight certain infections and respond to allergies and inflammation.
["Eosinophils help protect your body from parasites and allergic reactions, and elevated levels may signal an underlying condition."]
Key facts at a glance
- LOINC
- 102736-6
- Short code
- Endive IgG RAST
- Synonyms
- Endive IgG RAST
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- rast
- CPT
- 84484
- SNOMED
- 302774002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your doctor may order this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained allergies. It could also be done to check for conditions like parasitic infections, certain cancers, or autoimmune disorders.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw a small amount of blood. The process is quick and usually painless.
What the Results Mean
Elevated eosinophil counts may indicate allergies, infections, or conditions like asthma, eosinophilic esophagitis, or certain blood disorders. Lower-than-normal levels might suggest immune system issues or stress-related changes.
Common Conditions Linked to Eosinophil Counts
High eosinophil counts are often seen in allergic reactions, parasitic infections, or inflammatory diseases. Low levels can occur with stress, certain medications, or immune deficiencies.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated eosinophils can help diagnose conditions like allergic disorders, parasitic infections, or certain cancers (e.g., leukemia). Doctors may also use this test to monitor treatment progress in these cases.
Short name
Eosinophil count
Frequently asked questions
What causes eosinophils to be high?
What does it mean if my eosinophil count is low?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy