About White Blood Cells

White blood cells (WBCs) are the cells in our blood that fight infection. These cells defend the body against infecting organisms (bacteria and viruses, or what we call "germs") as well as against foreign agents. They fight infections that are in both the blood stream and the body tissues.

There are about 7,000 to 25,000 WBCs in one drop of blood. The number varies depending on whether or not they are currently fighting infection. These cells are formed in the bone marrow from stem cells. There is a variety of types of WBCs.

Some WBCs actually surround and digest the offending organism (bacteria or particle). Some release chemicals such as histamine which plays a role in the inflammatory response to infection. Some of the cells have digestive enzymes that are effective against parasitic worms. WBCs increase in the presence of allergic disorders. Some of the cell (T-lymphocytes) act against virus-infected cells and others (B-lymphocytes) produce protective antibodies that overpower invaders. B-lymphocytes may also be "memory cells" which are ready to fight if the same infection recurs.

Lowered WBCs can be a result of bone marrow failure, presence of cytotoxins (such as chemotherapy), collagen vascular diseases (such as lupus), disorders of the liver or spleen and radiation. Increased WBCs can be a result of inflammation (such as rheumatoid arthritis or allergy), leukemia, severe physical or emotional stress, and tissue damage such as burns and anemia.