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 allergies or inflammation.
Eosinophils help your body defend against parasites and allergies, and their count can signal underlying conditions.
Key facts at a glance
- LOINC
- 50373-0
- Short code
- Eosinophil band NFr Mar Manual
- Synonyms
- Eosinophil band NFr Mar 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
Doctors may order an eosinophil count to investigate symptoms like persistent itching, skin rashes, asthma, or unexplained infections. It can also help diagnose conditions such as allergies, parasitic infections, certain cancers, or inflammatory diseases.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. The process usually takes a few minutes, and you can resume normal activities afterward.
What the Results Mean
Eosinophil counts vary among individuals. High levels may indicate allergic reactions, parasitic infections, certain cancers (like lymphoma), or autoimmune disorders. Low levels might suggest immune suppression or other health issues. Your doctor will interpret the results in the context of your overall health and symptoms.
Common Conditions Linked to Eosinophil Counts
Elevated eosinophil counts are often associated with allergic conditions (e.g., asthma, hay fever), parasitic infections, certain cancers (e.g., leukemia), or chronic inflammatory diseases. Low eosinophil counts may occur with infections that suppress the immune system or certain medications.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Eosinophils play a key role in defending against parasites and managing allergic responses, but their abnormal levels can signal underlying health concerns that require further medical evaluation.
Short name
Eosinophil count
Frequently asked questions
What causes eosinophils to be high in my blood?
How long does it take to get my eosinophil test results?
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