Eosinophil count (fluid)
This test measures the number of eosinophils, a type of white blood cell, in a fluid sample (e.g., blood, lymph, or other bodily fluids). Eosinophils help fight infections and respond to allergies and inflammation.
["Eosinophils help your body fight certain infections and allergic reactions, and their levels can indicate health issues like allergies or parasitic infections."]
Key facts at a glance
- LOINC
- 35063-7
- Short code
- Eosinophil # Fld
- Synonyms
- Eosinophil # Fld
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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
What Is Eosinophil Count Testing Used For?
Eosinophil counts are often checked when doctors suspect conditions like allergic reactions, asthma, parasitic infections, or certain types of autoimmune diseases. They may also be evaluated in people with unexplained symptoms such as persistent itching, skin rashes, or digestive issues.
How Is This Test Performed?
A sample of fluid (like blood or lymph) is taken and examined under a microscope to count eosinophils. The test may be done as part of a complete blood count (CBC) or a specialized blood test. If a different fluid (e.g., cerebrospinal fluid) is used, it will be collected through a procedure like a spinal tap.
What Might Abnormal Results Indicate?
High eosinophil levels may suggest conditions like allergies, asthma, parasitic infections, or certain cancers (e.g., lymphoma). Low levels could indicate infections like tuberculosis or certain immune disorders. Your doctor will interpret results in the context of your symptoms and medical history.
Common Conditions Monitored with This Test
Doctors may use eosinophil counts to diagnose or monitor conditions such as allergic reactions, eosinophilic esophagitis, chronic eosinophilic leukemia, or parasitic infections like hookworm or strongyloidiasis.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Eosinophils play a key role in defending against certain parasites and managing allergic responses. Elevated levels often point to active inflammation or allergic processes, while low levels may signal immune suppression or specific infections. Always discuss your results with your healthcare provider for personalized interpretation.
Short name
Eosinophil Fluid Level
Frequently asked questions
Why might my doctor order this test?
What are typical reference ranges for this test?
Can I prepare for this test in any special way?
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