White blood cells are produced in bone marrow, lymph nodes, the spleen and thymus. They fight infection and foreign bodies and help distribute antibodies throughout the body. Unused, a white blood cell lives for two to three weeks, and then disintegrates.

May be Increased in the Presence of:

• Infection
• Hemorrhage
• Trauma
• Some malignancies
• Exposure to toxic substances
• Thyroid storm
• Renal failure
• Some drugs (quinine, adrenalin and others)
• Chronic inflammatory disease
• Stress reactions
• Exercise
• Heat
• Cold
• Anesthesia
• Cigarette smoking

May be Decreased in the Presence of:

• Viral infections
• Bone Marrow Disease
• Bone Marrow Depression, secondary to:
  • Analgesics
  • Antibiotics
  • Antihistamines
  • Anticonvulsants
  • Antiinflammatory drugs
  • Antithyroid drugs
  • Arsenic
  • Barbiturates
  • Chemotherapy
  • Diuretics
  • Heavy metal contamination
  • Radiation exposure

Special Considerations

• Smokers typically have elevated hematocrits in response to chronic, low-grade carbon monoxide poisoning and other mild respiratory ailments. Because of the carbon monoxide binding, they may still be functionally anemic, even though their hematocrit levels look good.
• Adaptation to high altitudes includes moderate elevation of hematocrit.
• During the initial phases of an acute hemorrhage, the hematocrit generally doesn't change very much. Later, as extracellular fluid is mobilized and IV fluids are incorporated, there is a dilutional effect that will lead to a reduced hematocrit. This fall in hematocrit may take several hours to develop.

Normal Values*

*These are general values taken from a variety of sources. The actual normal values may vary from lab to lab and from one type of testing protocol to another.

Bureau of Medicine and Surgery
Department of the Navy
2300 E Street NW
Washington, D.C
20372-5300

Operational Medicine
 Health Care in Military Settings
CAPT Michael John Hughey, MC, USNR
NAVMED P-5139
  January 1, 2001