Basophilsnfrbld
This test measures the percentage of basophils, a type of white blood cell, in your blood to help evaluate your immune system and detect certain medical conditions.
{"Basophils are the least common type of white blood cell, making up less than 1% of all white blood cells","This test helps diagnose allergic reactions, infections, and certain blood disorders","Abnormal basophil levels may indicate underlying health conditions that need further evaluation","The test is performed on a blood sample and is usually part of a complete blood count (CBC)","Results are interpreted alongside other white blood cell types for accurate diagnosis"}
Key facts at a glance
- LOINC
- 30180-4
- Short code
- BASO/WBC
- Synonyms
- Basophils NFr Bld
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA (lavender/purple-top) vacuum blood collection tube
- Units
- N/A
- Ref low
- 0.5
- Ref high
- 1
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Automated hematology analyzer using flow cytometry and impedance (e.g., Sysmex XN series, Beckman Coulter DxH, Abbott CELL-DYN)
- CPT
- 85025
- SNOMED
- 7051007
- Specimen volume
- 3-5 mL of whole blood (1 mL minimum for pediatric samples)
- Stability
- Stable for 4 hours at room temperature (20-25°C) or 24 hours refrigerated (2-8°C). Basophil counts should be performed within 2 hours of collection for optimal accuracy
- Hemolysis max
- 100
- Lipemia max
- 500
- Icterus max
- 50
- TAT
- 1–4 hours
- Order
- routine
What is this test?
The basophils test measures the percentage of basophils in your blood. Basophils are a type of white blood cell (leukocyte) that play an important role in your immune system. They are the least abundant type of white blood cell, typically making up less than 1% of all white blood cells in a healthy person.
Why is this test performed?
This test is usually performed as part of a complete blood count (CBC) with differential. Your healthcare provider may order this test to: evaluate your overall immune system health, investigate symptoms like unexplained allergic reactions, detect infections or inflammatory conditions, monitor certain blood disorders such as leukemia, or assess your response to certain treatments.
How is the test done?
A healthcare professional will draw a small sample of blood from a vein in your arm. The sample is then sent to a laboratory where it is analyzed using automated blood analyzers to determine the percentage and absolute count of basophils. The procedure is quick and generally takes only a few minutes.
What do the results mean?
Normal basophil levels typically range from 0 to 1% of total white blood cells, or approximately 0 to 0.1 x 10^9/L. Elevated basophil levels (basophilia) may indicate allergic reactions, chronic inflammation, infections (such as chickenpox or tuberculosis), certain leukemias, or autoimmune diseases. Low basophil levels (basopenia) are less common and may occur with hyperthyroidism, acute infections, prolonged stress, or as a side effect of certain medications.
Are there any risks?
The risks associated with this test are minimal and similar to any routine blood draw. You may experience slight bruising, bleeding, or dizziness at the puncture site. These symptoms usually resolve quickly. Serious complications are rare.
Reference range
Basophils: 0.5-1.0% of total leukocytes (absolute count: 0.02-0.10 x 10^3/µL). Leukocytes (WBC): 4.0-11.0 x 10^3/µLN/A
No special preparation required. Specimen should be collected prior to administration of medications that may affect white blood cell counts when possible
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
Can stress affect my basophil count?
What happens if my basophil count is abnormal?
Can allergies affect my basophil levels?
How often should this test be done?
Sources
- 1
- 2
- 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 15, 2026. · Read our editorial policy