White blood cells are made in the bone marrow and protect the
body against infection. If an infection develops, white blood cells attack and
destroy the bacteria, virus, or other organism causing it.
blood cells are bigger than red blood cells and normally are fewer in number.
When a person has a bacterial infection, the number of white cells can increase
The white blood cell count shows the number of white
blood cells in a sample of blood. A normal white blood cell count is between
4,500 and 11,000 cells per cubic millimeter (4.5 and 11.0 x
109 cells per liter). The number of white blood
cells is sometimes used to identify an infection or to monitor the body's
response to treatment.
There are five types of white blood cells:
lymphocytes, monocytes, neutrophils, basophils, and eosinophils.