WBC count

• A
• B
• C
• D
• E
• F
• G
• H
• I
• J
• K
• L
• M
• N
• O
• P
• Q
• R
• S
• T
• U
• V
• W
• X

Basophil (Close-up)

Formed elements of blood

White blood cell count - series

Leukocyte count; White blood cell count

Risks associated with having blood drawn are slight:

• excessive bleeding
• fainting or feeling light-headed
• hematoma (blood accumulating under the skin)
• infection (a slight risk any time the skin is broken)
• multiple punctures to locate veins

There are several types of white blood cells (WBCs) that normally appear in the blood: neutrophils (polymorphonuclear leukocytes; PMNs), band cells (slightly immature neutrophils), T-type lymphocytes (T cells), B-type lymphocytes (B cells), monocytes, eosinophils, and basophils.

Any infection or sudden stress will result in an increased production of WBCs. This usually means increased numbers of cells and an increase in the percentage of immature cells (mainly band cells) in the blood. This change is called a "shift to the left."

Interfering factors:

• Acute emotional or physical stress can increase WBC counts.
• People who have had their spleen removed (splenectomy) will have a persistent mild elevation of WBCs.
• Drugs that may increase WBC counts include epinephrine, allopurinol, aspirin, chloroform, heparin, quinine, corticosteroids, and triamterene.
• Drugs that may decrease WBC counts include antibiotics, anticonvulsants, antihistamine, antithyroid drugs, arsenicals, barbiturates, chemotherapeutic agents, diuretics, and sulfonamides.
• Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Review Date: 02/03/2005
Reviewed By: Rita Nanda, M.D., Department of Hematology/Oncology, University of Chicago Medical Center, Chicago, IL. Review provided by VeriMed Healthcare Network.