White Blood Cell Count (WBC)

Complete Blood Count

Normal Reference Ranges

Adult

4.5 - 11.0 x10³/µL

Pediatric

5.0 - 15.0 (varies by age) x10³/µL

Clinical Significance

Primary indicator of infection or inflammation. Needs differential (neutrophils, lymphocytes) for specific etiology.

Causes of High

  • Infection (bacterial)
  • Inflammation
  • Leukemia
  • Stress/Trauma
  • Corticosteroids

Causes of Low

  • Viral infections
  • Bone marrow failure
  • Chemotherapy
  • Autoimmune disease (Lupus)