Why Do White Blood Cells Rise?

The main function of white blood cells, or leukocytes, is to fight against injury and disease, making them a major part of the body's immune system. White blood cells increase in number when there is an allergic reaction or infection in the body.

Leukocytosis

• The increase of white blood cells in the body when an infection is present is called leukocytosis. This rise in number occurs to help the body defend itself.

Parasites

• Eosinophils, a type of white blood cell, release chemicals that can destroy pathogens. Their numbers increase if a parasitic infection is present in the body.

Allergic Reactions

• Eosinophils also increase in a person who is having an allergic reaction. The chemicals they secrete help destroy the allergen.

Inflammation

• If any body tissue is exposed to a trauma, such as a cut or a burn, white blood cells increase in numbers and quickly work to stop the invaders from harming the body. This might cause inflammation.

Pus

• During inflammation or infection of an area, pus is formed. This is a combination of white blood cells that got to the affected area through diapedesis and other fluids.

Leukemia

• There is a major increase in the number of leukocytes seen in patients with leukemia. These immature white cells replace the red blood cells of the body, interfering with the transport of oxygen to the body tissues.