Eosinophil Count (Manual Differential Blood Count)
This test measures the number of eosinophils, a type of white blood cell, in your blood. Eosinophils help fight certain infections and respond to allergic reactions.
["Eosinophils can signal inflammation or allergic responses, helping doctors diagnose conditions like allergies or infections."]
Key facts at a glance
- LOINC
- 40569-6
- Short code
- Eosinophil # Fld Manual
- Synonyms
- Eosinophil # Fld Manual
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- 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 Is Done
Your doctor may order this test if you have symptoms like persistent itching, skin rashes, asthma, or unexplained infections. It can also help monitor conditions like parasitic infections, certain cancers, or allergic disorders.
What to Expect Before the Test
No special preparation is needed. A blood sample is taken from a vein, usually in your arm, and sent to the lab for manual counting of eosinophils under a microscope.
What the Results Mean
Results are expressed as a count of eosinophils per microliter (µL) of blood. Higher-than-normal counts may indicate allergies, infections, or other inflammatory conditions. Lower-than-normal counts may suggest immune suppression or other health issues.
Possible Conditions Linked to Eosinophil Levels
Elevated eosinophil counts can be linked to allergies, asthma, parasitic infections, certain cancers (like leukemia), or autoimmune diseases. Low levels may be associated with immune disorders or chronic illnesses.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: Eosinophils play a key role in defending against parasites and managing allergic reactions. Elevated levels often point to ongoing inflammation or immune responses, guiding treatment for conditions like asthma, allergies, or parasitic infections. Doctors use these results to tailor therapies and monitor disease activity.
Short name
Eosinophil Level
Frequently asked questions
What causes eosinophil levels to rise?
What happens if my eosinophil count is high?
Can I eat or drink before 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 16, 2026. · Read our editorial policy