Basophils
The rarest white blood cells, involved in allergic and inflammatory responses.
Typical reference range
| Range | Unit |
|---|---|
| 0–0.1 | E9/l |
What Basophils measures
Basophils are the rarest of the white blood cells, usually making up only a tiny fraction of the total. Despite their small numbers, they play a part in the body's allergic and inflammatory responses. When activated, they release histamine and other chemical mediators that contribute to reactions such as itching, swelling, and the widening of blood vessels.
On a complete blood count with differential, basophils are reported both as a small absolute count and as a percentage of your white blood cells. Because the numbers involved are so low to begin with, basophils are best read as one strand within the whole blood picture rather than in isolation, and interpreted alongside your other results with a clinician.
What a high Basophils can mean
A high basophil count, sometimes called basophilia, is uncommon. When it does appear, it can be linked to allergic or inflammatory conditions, an underactive thyroid, or, less commonly, certain chronic blood conditions.
Because a genuinely raised basophil value is unusual, it is rarely meaningful on its own. A clinician will typically read it alongside the rest of the complete blood count and your broader clinical picture to judge whether it reflects something worth exploring or simply normal variation.
- Interpret it together with the full blood count, not as a standalone figure.
- Consider it in the context of any allergy, inflammation, or thyroid symptoms you may have.
- Any follow-up or further testing belongs with a clinician who knows your history.
What a low Basophils can mean
A low basophil count is difficult to interpret, because the normal number of basophils is already very low. Small shifts downward from an already tiny baseline rarely carry a clear meaning.
For this reason, a low basophil value is generally not considered clinically significant and does not call for any action on its own. It is most useful when read within the context of the whole complete blood count rather than as a single number.
- Treat it as part of the overall blood picture, not an isolated result.
- On its own, a low value typically needs no specific follow-up.
- Discuss what your complete blood count means for you with a clinician who knows your history.
Track your Basophils over time in Quanome — it reads your lab reports (PDF or photo) on your device, charts each marker against its range, and an AI coach explains what your trends mean alongside your Apple Health and DNA.