Eosinophil count (peripheral blood)
This test measures the number of eosinophils, a type of white blood cell, in your blood. Eosinophils help fight infections caused by parasites and play a role in allergic reactions.
["Eosinophil levels can help diagnose or monitor conditions like allergies, asthma, or certain infections."]
Key facts at a glance
- LOINC
- 29992-5
- Short code
- Eosinophil Nose Ql Wright Stn
- Synonyms
- Eosinophil Nose Ql Wright Stn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- wright-stain
- 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 to check for conditions affecting your immune system, such as allergies, asthma, parasitic infections, or certain blood disorders. It can also help evaluate symptoms like persistent itching, skin rashes, or unexplained fatigue.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm to draw blood, similar to a routine blood draw. The process takes about 5 minutes, and you may feel slight discomfort for a few seconds.
What the Results Mean
Eosinophil counts are usually reported as a percentage of total white blood cells or an absolute count (number per microliter of blood). While reference ranges vary by lab, elevated levels may suggest allergic reactions, infections, or other immune-related conditions.
Common Conditions Monitored
High eosinophil counts are often linked to allergies, asthma, parasitic infections, or inflammatory diseases. Low levels may indicate immune suppression or certain blood disorders.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Eosinophils are a type of white blood cell that increase in response to allergic reactions, parasitic infections, or chronic inflammatory conditions. Doctors use this test to guide treatment decisions, especially for patients with persistent symptoms like skin rashes, wheezing, or unexplained fevers.
Short name
Eosinophil CBC
Frequently asked questions
What causes eosinophil levels to rise?
How long does it take to get results?
Can diet or exercise affect eosinophil counts?
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