White Blood Cell Count (WBC)
White blood cell count reflects the total circulating leukocyte population. Females tend to have slightly higher counts than males in younger age groups, with the difference narrowing after age 50.
Unit: 1000 cells/uL · 12 slices · age and sex · 1 source
Filed under panels: Complete Blood Count · topics: Hematology
The white blood cell count measures total circulating leukocytes, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils. WBC varies with infection, inflammation, stress, medication use, and time of day. Population distributions are broad because many physiological and subclinical states influence the count.
Population Distribution
Browse by Demographic
| Age (years) | male (1000 cells/uL) | female (1000 cells/uL) |
|---|---|---|
| 20-29 | 4.3–10.9 (6.7) | 4.6–11.7 (7.5) |
| 30-39 | 4.6–11.2 (6.9) | 4.6–11.7 (7.3) |
| 40-49 | 4.3–11.4 (6.7) | 4–12.1 (7.2) |
| 50-59 | 4.4–10.6 (7) | 4.4–10.4 (6.9) |
| 60-69 | 4.4–11.1 (7) | 4.2–10.6 (6.6) |
| 70+ | 4.4–10.7 (6.8) | 4.2–11.3 (7) |
Frequently Asked Questions
Why is the WBC distribution so wide?
Many factors shift WBC counts: acute and chronic infection, inflammation, stress, smoking, medications, and even time of day. The population distribution includes all of these influences, producing a wide spread.
What does the total WBC count not tell you?
It does not distinguish which types of white cells are elevated or reduced. The WBC differential (neutrophils, lymphocytes, monocytes, eosinophils, basophils) provides that detail and is not included on this page.
Does WBC count decline with age?
Modestly, in both sexes. Total WBC tends to drift slightly lower in older adults, partly due to reduced bone marrow reserve and shifts in lymphocyte populations. However, the change is small relative to the population spread, and the distribution at any given age remains wide.