Basophils

Basophils are the least common white blood cells. They play a role in allergic reactions and release histamine during inflammation.

Category: Complete Blood Count

Also known as: basophils, baso, basophil %, basos, bazofili

Reference range: 0–1 % (Source: ABIM)

Standard unit: %

High values may indicate

High basophils (basophilia) may indicate allergic reactions, chronic myeloid leukemia, hypothyroidism, or inflammatory conditions.

Low values may indicate

Low basophils are generally normal, as they make up a very small percentage of white blood cells.

Frequently asked questions

What is a normal Basophils level?
A typical reference range for Basophils is 0–1 % (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
What units is Basophils measured in?
Basophils is most commonly reported in %. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
Where do Basophils reference ranges come from?
BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
Can I track Basophils over time?
Yes. Upload results from any lab and BloodId charts your Basophils over time against its reference range, so you can see whether the trend is rising, falling, or stable.

Related biomarkers

Source: MedlinePlus, U.S. National Library of Medicine

How we source our data

Analyze your Basophils with AI

Chart your Basophils over time

Track your Basophils over time with BloodId