Lupus Site - a guide for lupus patients and their families

A WBC count measures the number of white blood cells in a sample of blood. It is a valuable diagnostic tool for a number of diseases that is usually ordered as part of a complete blood count

This test is normally performed to detect an infection or inflammation.

A normal white blood cell count ranges from 4,500 to 10,000 cells/mcl (cells per microliter) of blood.

Abnormally low numbers of white blood cells may be caused by:

• bone marrow failure
• a bone marrow tumor
• a substance in the body that is toxic to these cells
• collagen-vascular diseases, such as rheumatoid arthritis or systemic lupus erythematosus
• liver disease
• spleen disease
• radiation

Abnormally high numbers of white blood cells may be caused by:

• allergy
• emotional or physical stress
• infectious diseases
• inflammatory diseases
• leukemia
• tissue damage