White Blood Cells (WBC)
CBCNormal range
4,500–11,000 /mm³
SI: 4.5–11.0 ×10⁹/L
Critical low: < 2,000 /mm³ · Critical high: > 30,000 /mm³
☎ When to call
New WBC > 30,000 or < 2,000, or any fever in a neutropenic patient — call the provider now; neutropenic fever is an emergency.
What you do
- Trend, don't spot-read — direction matters more than one value
- If low: neutropenic precautions, strict hand hygiene, monitor temp q4h
- If high with fever: anticipate cultures BEFORE antibiotics
Causes of HIGH white blood cells
Causes of LOW white blood cells
Source: Pagana, Mosby's Manual of Diagnostic and Laboratory Tests, 7th ed.Reference only — verify against your facility's policy.
