This page helps you to understand blood test results for White Cell Count and gives you the reference range to determine if your lab test results mean that you have a high, low or normal White Cell Count.
We outline the risk factors associated with both raised and lower White Cell Count.
Reference Ranges for White Cell Count:
|US Conventional Units||x10E3/uL = x10^9/L||3.5-10.5||<3.5 or >10.5|
|Standard International Units||x10E3/uL = x10^9/L||3.5-10.5||<3.5 or >10.5|
What are Red Blood Cells
White blood cells, also called leukocytes, are cells that exist in the blood, the lymphatic system, and tissues and are an important part of the body’s defense system.
Blood is made up of a few different types of cells suspended in fluid called plasma. In addition to WBCs, there are red blood cells and platelets. All of these cells are produced in the bone marrow and subsequently released into the blood .
There are five types of WBCs, and these are generally measured in isolation as well as part of the white blood cell analysis:
Lymphocytes – Your bone marrow constantly produces cells that will become lymphocytes. Some will enter your bloodstream, but most will move through your lymphatic system. The lymphatic system is the group of tissues and organs, like the spleen, tonsils, and lymph nodes that protect your body from infection .
Monocytes are a type of white blood cell that fights off bacteria, viruses and fungi. Monocytes are the biggest type of white blood cell in the immune system. Originally formed in the bone marrow, they are released into our blood and tissues. When certain germs enter the body, they quickly rush to the site for attack.
Neutrophils are the most plentiful type of white blood cell, making up 55 to 70 percent of your white blood cells. Neutrophils are important because, unlike some of the other white blood cells, they aren’t limited to a specific area of circulation. They can move freely through the walls of veins and into the tissues of your body to immediately attack all antigens .
Eosinophils – Eosinophils have two distinct functions in your immune system. They destroy invading germs like viruses, bacteria, or parasites, and they also create an inflammatory response, especially if an allergy is involved. Allergies are immune responses that often involve chronic inflammation. Eosinophils play a significant role in the inflammation related to allergies and asthma .
Basophils – Basophils contain heparin. This is a naturally occurring blood-thinning substance, which prevents blood clotting. Basophils are also thought to mediate allergic reactions by releasing histamine. Basophils play a role in causing the body to produce the antibody called immunoglobulin E (IgE) which binds to basophils and a similar type of cell called mast cells. These cells release substances such as histamines and serotonin. They mediate the inflammatory response in the area of your body that was exposed to the allergen .
Function of White Blood cells
In general, WBC’s help protect against infections and also have a role in inflammation, allergic responses, and protecting against cancer. The white blood cell (WBC) count totals the number of white blood cells in a person’s sample of blood. It is one test among several that is included in a complete blood count (CBC), which is often used in the general evaluation of a person’s health.
When there is an infection or an inflammatory process somewhere in the body, the bone marrow produces more WBCs, releasing them into the blood, and through a complex process, they move to the site of infection or inflammation. As the condition resolves, the production of WBCs by the bone marrow subsides and the number of WBCs drops to normal levels again.
Risk factors associated White Cell Count
A WBC count can indicate that there is a disease or condition affecting white blood cells, but it cannot determine the underlying cause. In addition to infections and inflammation, there are a number of conditions that can affect the production of WBCs by the bone marrow or the survival of WBCs in the blood,
Some diseases trigger a response by the immune system and cause an increase in the number of WBCs. Other conditions affect the production of WBCs by the bone marrow or the survival of WBCs in the circulation, resulting in either an increase or decrease in the number of circulating WBCs .
Notable variations by demographic group
- White blood cell count decrease slightly in the elderly
- White blood cell count is increased in pregnancy as the immune system has to adjust itself to support the mother and her unborn baby. The production of white blood cells further increases when the mother nears her time for birth due to increased physiologic stress