White Blood Cells

Normal and Abnormal White Blood Cell Counts

A normal white blood cell (WBC) count for an adult is between 3,500 and 10,500 white blood cells per microliter of blood. Infants can have a WBC count as high as 30,000. This seemingly off-the-charts count is not abnormal, and will gradually fall until adulthood.

Why the Body Needs White Blood Cells

There are five types of white blood cells the function in different ways. In general, white blood cells help defend the body from bacteria and viruses that can cause infection. They are also involved in fighting cancer and can filter poisons, waste products or damaged cells from the blood.

Factors that Influence WBC Values

The are many reasons for an abnormal WBC count. Severe infections, some antibiotics, or autoimmune disease can all reduce the WBC count. Some conditions behind an excessive number of white blood cells include strong immune response, certain medications, and immune system malfunction.

How WBC Count is Measured

WBC count is measured using a simple blood test. A nurse or other healthcare worker cleans the skin over an arm or hand with a disinfectant and then ties an elastic band over the upper arm to help blood fill the vein. Then, a new, small needle is inserted through the skin to collect blood. This blood sample gets transported to a laboratory for testing.

Interesting Facts About White Blood Cells

Although they can defend the whole body, white blood cells make up less than one-percent of its cells. These hard workers can live from hours to years. WBC lifespan primarily depends on the type.