Helvy
Full Blood Count
In the UK, the standard clinical (NHS) reference range for White Blood Cell Count (WBC) is 4.0-11.0 ×10⁹/L, with 4.5-6.5 ×10⁹/L considered the performance-optimised range. A result within these ranges suggests typical status; only a qualified clinician can interpret an individual reading.
White blood cell count is the total number of circulating leukocytes — neutrophils, lymphocytes, monocytes, eosinophils, and basophils — measured in ×10⁹ cells per litre of blood. It is the first-line marker of acute infection, but its real value sits at the chronic end: persistent low-grade elevation is one of the most reliable predictors of cardiovascular events, cancer, and mortality. WBC is the ninth biomarker in the Levine PhenoAge composite.
Optimal range · UK
4.5-6.5 ×10⁹/L
Performance-optimised band · clinical (NHS) range 4.0-11.0 ×10⁹/L
Reference ranges for WBC, not a personal result. Any individual reading should be interpreted by a qualified clinician.
Optimal ranges
| Range | Value |
|---|---|
| Clinical (NHS) reference range | 4.0-11.0 ×10⁹/L |
| Performance-optimised range | 4.5-6.5 ×10⁹/L |
The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best. A result in either range suggests typical status and is not a diagnosis; any individual reading should be interpreted by a qualified clinician.
Why it matters
Most people focus on whether WBC is high enough to fight infection. The longevity story is the opposite: a chronically elevated WBC, even within the 'normal' 4-11 range, is a smoking gun for chronic inflammation. A baseline WBC above 7 carries roughly twice the mortality risk of a baseline below 5, independent of CRP. The performance target sits in the 4.5-6.5 range — high enough for robust immune function, low enough to reflect a quiet inflammatory environment.
Symptoms
Low / Deficiency
High / Excess
Dietary sources
Supplementation
If WBC is chronically elevated, the protocol is anti-inflammatory: address visceral adiposity, sleep quality, periodontal health, and any low-grade gut or oral infections. Omega-3 at 2-3 g EPA+DHA daily lowers WBC and CRP in published trials. Curcumin (with piperine) and vitamin D sufficiency both contribute. Direct WBC suppression is never the goal — the goal is removing the inflammatory stimulus.
Testing
WBC is measured from a blood sample. With Helvy, that means a finger-prick kit taken at home and posted to a UKAS-accredited UK laboratory, with results in around 5 days, reviewed by a qualified clinician. Your result is reported against both the clinical range (4.0-11.0 ×10⁹/L) and the performance-optimal range (4.5-6.5 ×10⁹/L), so you can see not just whether you are “normal” but whether you are optimal. If you make a change, retest after 8-12 weeks to confirm it worked.
Research
An epigenetic biomarker of aging for lifespan and healthspan
Levine ME, Lu AT, Quach A, et al.
Aging (Albany NY) (2018)
DOI: 10.18632/aging.101414Related biomarkers
Related guides
This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.
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