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 infections caused by parasites and play a role in allergic reactions.
Eosinophils help protect your body from certain infections and allergies.
Key facts at a glance
- LOINC
- 12210-1
- Short code
- Eosinophil NFr UrnS Manual
- Synonyms
- Eosinophil NFr UrnS Manual
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Might You Need This Test?
Your healthcare provider may order this test to diagnose or monitor conditions like allergies, asthma, parasitic infections, or certain blood disorders. It can also help assess how your body is responding to treatments for these conditions.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein, but this is not always required for manual differential counts. Bring any medications or supplements you’re taking to your appointment.
What Happens During the Test?
A healthcare professional will draw a small amount of blood from a vein in your arm. The blood sample is then examined under a microscope by a trained technician to count eosinophils among other white blood cells. This process is called a manual differential blood count.
What Are the Results Measured Against?
Results are typically reported as the absolute count of eosinophils per microliter (µL) of blood. While reference ranges vary by lab, elevated eosinophil counts may suggest certain conditions, and lower counts may indicate other health concerns.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated eosinophil counts can signal conditions such as allergies, asthma, parasitic infections, or certain autoimmune diseases. Low eosinophil counts might be associated with infections like tuberculosis, certain cancers, or immune deficiencies. Your provider will interpret results in the context of your symptoms and medical history.
Short name
Eosinophil Count
Frequently asked questions
What causes eosinophils to be high?
What does it mean if my eosinophil count is low?
Can I influence my eosinophil count?
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