White blood cell count (WBC)
The white blood cell count is the number of leukocytes in blood. US survey ranges for adults run from about 3.8 to 12.9 thousand/µL, and a Nordic interval is 3.5 to 8.8. Ranges in Black adults start lower, a difference tied to the Duffy-null gene variant. Higher counts were linked to more heart disease, diabetes and deaths.
- Status
- Part of the complete blood count, ordered by a clinician and also sold direct to consumers by some US laboratories. FDA classifies automated cell counters, which count red cells, white cells and platelets, as class II devices [1].
- Measures
- The number of white blood cells (leukocytes) of all types in a given volume of whole blood, counted by an automated cell counter.
- Also called
- WBC, WBC count, white blood cell count, white cell count, total white count, leukocyte count, leucocyte count, leukocytes, total leukocytes
- Tested for
- infection, inflammation, immune health, general checkup, monitoring during medication, low white count in people of African ancestry, heart disease risk
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Linked in research3
- StrongLinked to more coronary heart disease at higher counts, about 40% more in the top third than the bottom third across pooled prospective studies.
- ModerateLinked to more deaths at higher counts, about 10% more for each 1 thousand/µL in a meta-analysis of 13 studies.
- ModerateLinked to more type 2 diabetes at higher counts, 61% more in the top third than the bottom third, an estimate its authors consider too high.
Reported risks0
No risks sourced yet.
Reference ranges
Each range is the one its source published, in thousand/µL. Also reported in ×10⁹/L. Where sources differ, each is shown.
US national survey laboratory procedure manual, 2017 to 2018, men aged 19 to 65
Men aged 19 to 65, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 3.9 thousand/µL | No name given |
| 3.9 to 11.8 thousand/µL | "reference range" |
| above 11.8 thousand/µL | No name given |
The 2.5th to 97.5th percentiles of everyone measured in the US national survey from 1999 to 2004, calculated by ranking, without screening out smokers or people with illness, and without separating people by ancestry. The survey reports the count in thousands of cells per µL, which is the same number as ×10⁹ per liter [2].
US national survey laboratory procedure manual, 2017 to 2018, men aged 66 and older
Men aged 66 and older, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 3.8 thousand/µL | No name given |
| 3.8 to 12.1 thousand/µL | "reference range" |
| above 12.1 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
US national survey laboratory procedure manual, 2017 to 2018, women aged 19 to 65
Women aged 19 to 65, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 4.1 thousand/µL | No name given |
| 4.1 to 12.9 thousand/µL | "reference range" |
| above 12.9 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
US national survey laboratory procedure manual, 2017 to 2018, women aged 66 and older
Women aged 66 and older, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 4 thousand/µL | No name given |
| 4 to 11.6 thousand/µL | "reference range" |
| above 11.6 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
US national survey laboratory procedure manual, 2017 to 2018, boys aged 1 to 5
Boys aged 1 to 5, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 4.3 thousand/µL | No name given |
| 4.3 to 14.6 thousand/µL | "reference range" |
| above 14.6 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
US national survey laboratory procedure manual, 2017 to 2018, boys aged 6 to 18
Boys aged 6 to 18, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 3.6 thousand/µL | No name given |
| 3.6 to 11.5 thousand/µL | "reference range" |
| above 11.5 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
US national survey laboratory procedure manual, 2017 to 2018, girls aged 1 to 5
Girls aged 1 to 5, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 4.3 thousand/µL | No name given |
| 4.3 to 14 thousand/µL | "reference range" |
| above 14 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
US national survey laboratory procedure manual, 2017 to 2018, girls aged 6 to 18
Girls aged 6 to 18, as the reference range used by the survey laboratory · [2]
| Range | What the source calls it |
|---|---|
| below 3.9 thousand/µL | No name given |
| 3.9 to 12.2 thousand/µL | "reference range" |
| above 12.2 thousand/µL | No name given |
Derived the same way from the 1999 to 2004 survey sample [2].
Nordic Reference Interval Project, 2004
Adults aged 18 to 90 in Denmark, Finland, Iceland, Norway and Sweden · [3]
| Range | What the source calls it |
|---|---|
| below 3.5 thousand/µL | No name given |
| 3.5 to 8.8 thousand/µL | "reference interval" |
| above 8.8 thousand/µL | No name given |
The 2.5th to 97.5th percentiles in 1,826 healthy men and women, measured on 12 types of analyzer in 60 laboratories. One interval is given for both sexes. Its upper limit is 3 to 4 thousand/µL under the upper limits of the US survey ranges, which were not limited to healthy people [2][3].
Race-specific reference intervals from a US national survey, Lim and colleagues, 2010, Black men
Non-Hispanic Black men older than 18 · [4]
| Range | What the source calls it |
|---|---|
| below 3.1 thousand/µL | No name given |
| 3.1 to 9.9 thousand/µL | "reference interval" |
| above 9.9 thousand/µL | No name given |
The 2.5th to 97.5th percentiles in a US national survey after excluding people with low ferritin, pregnancy, obesity, or raised blood pressure, creatinine or glucose. The authors report that these limits are significantly lower than those for non-Hispanic white and Mexican American adults [4]. The lower counts in people of African ancestry are associated with the Duffy-null variant, a change in one gene that predicted white cell and neutrophil counts in 6,005 African Americans [5]. In 120 healthy Black adults at one US clinic, 66.7% had the Duffy-null blood type. Their median neutrophil count was 2,820 per µL against 5,005 in the others, and 23.8% of them, all selected as healthy, fell under the clinic's neutrophil reference limit of 2,000. The authors call the pattern Duffy-null associated neutrophil count [6]. This page does not give ranges for the neutrophil count, which is a separate result.
Race-specific reference intervals from a US national survey, Lim and colleagues, 2010, Black women
Non-Hispanic Black women older than 18 · [4]
| Range | What the source calls it |
|---|---|
| below 3.4 thousand/µL | No name given |
| 3.4 to 11 thousand/µL | "reference interval" |
| above 11 thousand/µL | No name given |
Derived the same way. In the same national survey, Black participants had a mean white cell count 0.89 thousand/µL lower than white participants, and a neutrophil count below 1,500 per µL was found in 4.5% of Black, 0.79% of white and 0.38% of Mexican American participants [7].
Race-specific reference intervals from a US national survey, Lim and colleagues, 2010, Black boys aged 12 to 18
Non-Hispanic Black boys aged 12 to 18 · [4]
| Range | What the source calls it |
|---|---|
| below 3.2 thousand/µL | No name given |
| 3.2 to 9.3 thousand/µL | "reference interval" |
| above 9.3 thousand/µL | No name given |
Derived the same way, with the same exclusions [4].
Race-specific reference intervals from a US national survey, Lim and colleagues, 2010, Black girls aged 12 to 18
Non-Hispanic Black girls aged 12 to 18 · [4]
| Range | What the source calls it |
|---|---|
| below 3.7 thousand/µL | No name given |
| 3.7 to 10.1 thousand/µL | "reference interval" |
| above 10.1 thousand/µL | No name given |
Derived the same way, with the same exclusions [4].
What has been shown to move it
Shown to lower it2
Small drops in blood counts and albumin
Small drops in hematocrit, hemoglobin, white cells and albumin were seen on terazosin in trials, which the label attributes to blood dilution. PSA did not change.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Small but statistically significant decreases in hematocrit, hemoglobin, white blood cells, total protein and albumin were seen in controlled trials. Treatment for up to 24 months had no significant effect on PSA [19].
- Population
- People in terazosin controlled trials [19].
- Sources
- [19]
- Caveats
- The label gives no size for the drops.
Fenofibrate: blood counts
The label reports mild to moderate drops in hemoglobin, hematocrit and white cells after starting fenofibrate that then stabilized, with rare low platelets or white cells.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- Mild to moderate decreases in hemoglobin, hematocrit and white blood cells were observed after starting fenofibrate and stabilized with long-term use. Thrombocytopenia and agranulocytosis have been reported [7].
- Population
- People starting fenofibrate [7].
- Sources
- [7]
- Caveats
- The label gives no sizes or rates.
Shown to raise it1
Raised white blood cell count
One study of 80 patients found prednisone raised the white blood cell count, in some above 20,000 per cubic millimeter, mainly through neutrophils.
The numbers and sources
- How common
- How often is not known: the sources give no rate.
- Effect
- In 80 patients, the white blood cell count rose on prednisone, passing 20,000 per cubic millimeter as early as the first day in some, peaking within 2 weeks in most and then falling without returning to pretreatment levels. The rise was mainly in neutrophils, with fewer eosinophils and a variable fall in lymphocytes. More than 6% band forms was rare, which the authors offer as a way to tell the change from infection [30].
- Population
- 80 patients treated with prednisone [30].
- Sources
- [30]
- Caveats
- One uncontrolled study from 1981. The abstract gives no mean change.
Tested, and not shown to change it1
Immune function in athletes
Not shown to change lymphocyte or leukocyte counts in athletes.
The numbers and sources
- Effect
- Glutamine did not change lymphocyte or leukocyte counts. Neutrophils fell at doses above 200 mg per kg (WMD -605.77), and glutamine dipeptide raised post-exercise blood glucose by 0.51 mmol/L [1].
- Population
- Athletes [1].
- Sources
- [1]
- Caveats
- Cell counts are not infection rates. The neutrophil confidence interval as printed (-1200.0 to 52.1) crosses zero, which conflicts with its reported p-value of 0.03 [1].
How it compares with the reference method
Mixed results1
Variation from one draw to the next in one person
Shown to vary about 11% from one draw to the next within the same person, in a pooled estimate from a European laboratory federation.
The numbers and sources
- Compared with
- The same person's results on repeated venous draws
- Effect
- The European Federation of Clinical Chemistry and Laboratory Medicine database gives a pooled within-person variation of 11.1% for the white cell count, with lower and upper limits of 8.9% and 15.9%, from 9 included estimates. Variation between people is 17.3%. For the neutrophil count the within-person figure is 14.6% [12]. At a count of 7.0 thousand/µL, 11.1% is about 0.8 thousand/µL.
- Population
- Healthy adults in the studies the database pools [12].
- Sources
- [12]
- Caveats
- A summary across studies in healthy volunteers. The database states no threshold for agreement, so the result is given as numbers only [12]. A result near the edge of a range may fall on the other side of it at the next draw.
What studies tie it to
Linked in research3
Coronary heart disease
Linked to more coronary heart disease at higher counts, about 40% more in the top third than the bottom third across pooled prospective studies.
The numbers and sources
- Effect
- In a meta-analysis of the 7 largest prospective studies, people in the top third of white cell count had a risk ratio for coronary heart disease of 1.4 (95% CI 1.3 to 1.5) against the bottom third, a difference of 8.4 against 5.6 thousand/µL [8]. A later meta-analysis by cell type found the neutrophil count had the strongest association (risk ratio 1.33, 95% CI 1.17 to 1.50, top against bottom third), with substantial differences between studies. In its own US cohort the figure for neutrophils was 1.09 (0.93 to 1.29) [9].
- Population
- 5,337 coronary heart disease cases in 7 long-term prospective studies [8]. 1,764 cases in 5 prospective studies, including 4,625 US adults followed 18 years [9].
- Sources
- [8], [9]
- Caveats
- Observational. The authors of the first analysis state that the mechanisms are not clear and call for further study of whether the association is causal [8].
Death from any cause
Linked to more deaths at higher counts, about 10% more for each 1 thousand/µL in a meta-analysis of 13 studies.
The numbers and sources
- Effect
- Each 1.0 thousand/µL higher white cell count had a pooled hazard ratio for death of 1.10 (95% CI 1.08 to 1.13). It was 1.10 (1.07 to 1.12) in people with cardiovascular disease and 1.12 (1.07 to 1.17) in the general population or people with COVID-19. For long-term death from any cause it was 1.09 (1.07 to 1.12), and for long-term cardiovascular death 1.05 (1.02 to 1.07) [10].
- Population
- 62,904 participants in 13 studies [10].
- Sources
- [10]
- Caveats
- Observational, and the pooled studies mixed patients with heart disease, people with COVID-19 and the general population. The authors state that causality is not established [10].
Type 2 diabetes
Linked to more type 2 diabetes at higher counts, 61% more in the top third than the bottom third, an estimate its authors consider too high.
The numbers and sources
- Effect
- In a meta-analysis of 20 studies, the relative risk of type 2 diabetes was 1.61 (95% CI 1.45 to 1.79) for the top against the bottom third of white cell count, with large differences between studies (I² 83%). In cohort studies alone it was 1.48 (1.22 to 1.79). In one English cohort the hazard ratio fell from 2.19 to 1.82 after accounting for smoking, family history, activity, education and body size [11].
- Population
- 8,647 people with type 2 diabetes and 85,040 without, in 20 cross-sectional and prospective studies [11].
- Sources
- [11]
- Caveats
- Observational. The authors found publication bias and incomplete control for confounders, and describe the observed association as likely an overestimate [11].
Sources
- US Food and Drug Administration. 21 CFR 864.5200, Automated cell counter. Electronic Code of Federal Regulations. https://www.ecfr.gov/current/title-21/section-864.5200
- Centers for Disease Control and Prevention, National Center for Health Statistics. National Health and Nutrition Examination Survey 2017-2018 Laboratory Procedure Manual: Complete Blood Count, whole blood, Beckman Coulter DxH 800 analyzer. Performed by the NHANES Mobile Examination Center. https://wwwn.cdc.gov/nchs/data/nhanes/public/2017/labmethods/CBC-J-MET-508.pdf
- Nordin G, Mårtensson A, Swolin B, et al. A multicentre study of reference intervals for haemoglobin, basic blood cell counts and erythrocyte indices in the adult population of the Nordic countries. Scandinavian Journal of Clinical and Laboratory Investigation. 2004. https://doi.org/10.1080/00365510410002797
- Lim EM, Cembrowski G, Cembrowski M, et al. Race-specific WBC and neutrophil count reference intervals. International Journal of Laboratory Hematology. 2010. https://doi.org/10.1111/j.1751-553X.2010.01223.x
- Reich D, Nalls MA, Kao WH, et al. Reduced Neutrophil Count in People of African Descent Is Due To a Regulatory Variant in the Duffy Antigen Receptor for Chemokines Gene. PLoS Genetics. 2009. https://doi.org/10.1371/journal.pgen.1000360
- Merz LE, Story CM, Osei MA, et al. Absolute neutrophil count by Duffy status among healthy Black and African American adults. Blood Advances. 2023. https://doi.org/10.1182/bloodadvances.2022007679
- Hsieh MM, Everhart JE, Byrd-Holt DD, et al. Prevalence of Neutropenia in the U.S. Population: Age, Sex, Smoking Status, and Ethnic Differences. Annals of Internal Medicine. 2007. https://doi.org/10.7326/0003-4819-146-7-200704030-00004
- Danesh J, Collins R, Appleby P, Peto R. Association of Fibrinogen, C-reactive Protein, Albumin, or Leukocyte Count With Coronary Heart Disease: Meta-analyses of Prospective Studies. JAMA. 1998. https://doi.org/10.1001/jama.279.18.1477
- Wheeler JG, Mussolino ME, Gillum RF, Danesh J. Associations between differential leucocyte count and incident coronary heart disease: 1764 incident cases from seven prospective studies of 30 374 individuals. European Heart Journal. 2004. https://doi.org/10.1016/j.ehj.2004.05.002
- Park C, Yoo K, Lee S, et al. The Prognostic Significance of Leukocyte Count on All-Cause and Cardiovascular Disease Mortality: A Systematic Review and Meta-Analysis. The American Journal of Cardiology. 2023. https://doi.org/10.1016/j.amjcard.2023.06.119
- Gkrania-Klotsas E, Ye Z, Cooper AJ, et al. Differential White Blood Cell Count and Type 2 Diabetes: Systematic Review and Meta-Analysis of Cross-Sectional and Prospective Studies. PLoS ONE. 2010. https://doi.org/10.1371/journal.pone.0013405
- European Federation of Clinical Chemistry and Laboratory Medicine. EFLM Biological Variation Database, meta-analysis estimates, read 2026-11-13. https://biologicalvariation.eu/