Is my Basophils (%) normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal Basophils level?
Basophils are the rarest circulating white blood cells, normally comprising 0-1% of total WBC. They release histamine and heparin and play roles in allergic reactions and parasitic defense. Elevated basophils (basophilia) above 2% are uncommon and may indicate myeloproliferative disorders (especially CML), allergic conditions, or hypothyroidism.
| Range | Values |
|---|---|
| Standard Reference | 0–1 % |
| High Risk | > 2 % |
What causes abnormal Basophils levels?
Elevated basophils: chronic myeloid leukemia (CML — the most important association), other myeloproliferative neoplasms (polycythemia vera, myelofibrosis), allergic conditions, hypothyroidism, ulcerative colitis, chronic sinusitis, and iron deficiency. Basophilia with a markedly elevated WBC and left shift should prompt immediate evaluation for CML with BCR-ABL testing.
When should you see a doctor?
See your doctor if basophil percentage is above 2%, especially with an elevated total WBC count. Basophilia in the context of leukocytosis, splenomegaly, or constitutional symptoms (fatigue, night sweats, weight loss) warrants urgent hematologic evaluation. Isolated mild basophilia without other CBC abnormalities is less concerning.
Basophils and longevity
Basophils are the least studied white blood cell but are gaining attention for their role in immune regulation. In the context of routine blood work, basophilia serves primarily as a red flag for myeloproliferative disorders, which increase in incidence with age. CML is highly treatable with tyrosine kinase inhibitors (imatinib), making early detection through CBC monitoring valuable.
Where to get a Basophils test
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Related biomarkers
These biomarkers are often tested alongside Basophils for a more complete picture.
Frequently asked questions
What is a normal basophil percentage?
What causes elevated basophils?
Are basophils related to allergies?
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Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.