Source-checked
Haematology
White blood cell count (WBC)
Source-checked · Content last updated · 1 min read ·
This is the date the draft was written, not a medical review date.
The total leucocyte count is a screening measure of marrow response, infection, inflammation and haematological malignancy. It is interpreted with the differential count.
Reference interval
| Conventional (x10^3/µL) | SI (x10^9/L) | |
|---|---|---|
| Adults | 4–11 x10^3/µL | 4–11 x10^9/L |
Specimen: Whole blood (EDTA) · Conventional × 1 = SI
Causes of high values
Bacterial infection, inflammation, tissue necrosis, corticosteroids, smoking, physiological stress, pregnancy and leukaemias or myeloproliferative disease.
Causes of low values
Viral infection, severe sepsis, marrow suppression (drugs, radiation, infiltration), autoimmune disease, hypersplenism and nutritional deficiencies.
Pre-analytical and method notes
Reference intervals vary with age (higher in infancy), pregnancy and ethnicity; some healthy populations, notably of African ancestry, have lower neutrophil counts. Automated counts can be affected by nucleated red cells and platelet clumping.
References
- Rifai N, Horvath AR, Wittwer CT. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Elsevier, 6th edition (2018) — Tier 3 (textbook)
- McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. Elsevier — Tier 3 (textbook)
- Loscalzo J, et al.. Harrison's Principles of Internal Medicine. McGraw-Hill, 21st edition (2022) — Tier 3 (textbook)
References are listed only where the article cites them. See the sources page for the full policy. How sources are chosen and credited