White Blood Cell Count
The Test
How is it used?
The WBC count is used to determine the presence of an infection or leukemia. It is also used to help monitor the body’s response to various treatments and to monitor bone marrow function.
When is it ordered?
What does the test result mean?
A decreased WBC count is called leukopenia. It can result from many different situations, such as chemotherapy, radiation therapy, or diseases of the immune system.
Counts that continue to rise or fall to abnormal levels indicate that the condition is getting worse. Counts that return to normal indicate improvement.
Is there anything else I should know?
If you have had your spleen removed, you may have a persistent mild to moderate increased WBC count.
The WBC count tends to be lower in the morning and higher in the late afternoon. WBC counts are age-related.
On average, normal newborns and infants have higher WBC counts than adults. It is not uncommon for the elderly to fail to develop leukocytosis as a response to infection.
There are many drugs that cause both increased and decreased WBC counts.
Smoking may also cause an increased WBC count.
