Blood test

Normal WBC count in the blood

Blood test
Normal WBC count in the blood
Last update: 21/01/2021

What is the normal count of WBC in the blood?

The normal count of WBC in the blood is age-dependent:

Adult men: 4.5 - 10.5 x 103/µl (microliter)
Adult women: 4.5 - 10.5 x 103/µl (microliter)
Children from 6 to 18 years old: 4.8 - 10.8 x 103/µl (microliter)
Children from 2 months old to 6 years old: 5 - 19 x 103/µl (microliter)
Babies from 2 weeks old to 2 months old: 5 - 21 x 103/µl (microliter)
Newborns (up to 14 days old): 9 - 30 x 103/µl (microliter)

Why normal levels can differ across different labs?

Each laboratory must establish its own normal ranges for WBC count in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels, according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.

Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.

Some circumstances can alter the normal ranges:

  • Black people have a lower normal level of WBC of about a 10%. Normal WBC count in adult black people may be as low as 3.2-10 x 103/µl.
  • During pregnancy, WBC count is higher than normal. The leukocytosis of pregnancy (up to 16 x 103) is due mostly to an increase in the neutrophils, with only a slight increase in lymphocytes.

What is WBCs (White Blood Cell) count?

WBC count is the total number of WBCs in a cubic millimeter of blood (/mm 3)

WBCs, also called leukocytes, fight infection and defend the body by a process called phagocytosis, in which the leukocytes actually encapsulate foreign organisms and destroy them. Leukocytes also produce, transport, and distribute antibodies as part of the immune response to a foreign substance (antigen).

The endocrine system is an important regulator of the number of leukocytes in the blood. Hormones affect the production of leukocytes in the blood-forming organs, their storage and release from the tissue, and their disintegration. For example, a local inflammatory process exerts a definite chemical effect on the mobilization of leukocytes.

The life span of leukocytes varies from 13 to 20 days, after which the cells are destroyed in the lymphatic system; many are excreted from the body in fecal matter.

White blood cells (or leukocytes) are divided into two main groups:

  • Polymorphonuclear leukocytes: They have distinctive granules in the cytoplasm and a multilobed nucleus. Neutrophils, basophils, and eosinophils belong to this group.
  • Mononuclear leukocytes: They do not contain distinctive granules and have nonlobular nuclei that are not necessarily spherical. Lymphocytes and monocytes belong to this group.

What is the WBC count used for?

The WBC count is usually performed in a routine blood test and provide information about many diseases and their progress. The WBC count serves as a useful guide to the severity of the disease process.

Specific patterns of leukocyte response are expected in various types of diseases as determined by the differential count (percentages of the different types of leukocytes) and it may be helpful for the diagnosis.

It is interesting to know the intrinsic WBC count of a person to detect any changes in the normal values.

A high WBC count is called leukocytosis and occurs in acute infections (mainly bacterial), in which the degree of increase of leukocytes depends on severity of the infection. Increased WBC counts may also be associated with stress, intense exercise, trauma, inflammation, and pain. Smoking may also cause slight leukocytosis. In addition, white blood cell counts are usually elevated well above the normal range in the presence of leukemia.

A low WBC count is called leukopenia and it is typical of chronic viral infection, immunodeficiency diseases or bone marrow disorders. Exposure to lead, mercury, some chemotherapy agents, and radiation may also cause the white blood cell count to be diminished.

Where can I find more information about WBC count in the blood?

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Which values are considered a normal WBC count in the blood?

The following values are considered to be normal values:

IMPORTANT: These levels are expressed in number/µl (microliter). They are an example of a healthy woman of about 45 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

WBC Count
4.5 x 103/µl4.6 x 103/µl4.7 x 103/µl4.8 x 103/µl4.9 x 103/µl5 x 103/µl5.1 x 103/µl5.2 x 103/µl
5.3 x 103/µl5.4 x 103/µl5.5 x 103/µl5.6 x 103/µl5.7 x 103/µl5.8 x 103/µl5.9 x 103/µl6 x 103/µl
6.1 x 103/µl6.2 x 103/µl6.3 x 103/µl6.4 x 103/µl6.5 x 103/µl6.6 x 103/µl6.7 x 103/µl6.8 x 103/µl
6.9 x 103/µl7 x 103/µl7.1 x 103/µl7.2 x 103/µl7.3 x 103/µl7.4 x 103/µl7.5 x 103/µl7.6 x 103/µl
7.7 x 103/µl7.8 x 103/µl7.9 x 103/µl8 x 103/µl8.1 x 103/µl8.2 x 103/µl8.3 x 103/µl8.4 x 103/µl
8.5 x 103/µl8.6 x 103/µl8.7 x 103/µl8.8 x 103/µl8.9 x 103/µl9 x 103/µl9.1 x 103/µl9.2 x 103/µl
9.3 x 103/µl9.4 x 103/µl9.5 x 103/µl9.6 x 103/µl9.7 x 103/µl9.8 x 103/µl9.9 x 103/µl10 x 103/µl
10.1 x 103/µl10.2 x 103/µl10.3 x 103/µl10.4 x 103/µl10.5 x 103/µl   
Medically reviewed by our Medical staff on 21/01/2021


  • A Manual of Laboratory and Diagnostic Test. 9th edition. Frances Fischbach. Marshall B. Dunning III. 2014. Pag 67. ISBN-10: 1451190891.
  • Laboratory tests and diagnostic procedures with nursing diagnoses (8th ed), Jane Vincent Corbett, Angela Denise Banks, ISBN: 978-0-13-237332-6, Pag. 46.
  • Essentials of Medical Laboratory Practice. Constance L. Lieseke, Elizabeth A. Zeibig. 2012. ISBN: 978-0-8036-1899-2 Pag: 272.
  • Common Terminology Criteria for Adverse Events (CTCAE). Version 5.0.Published: November 27, 2017. U.S. Department of health and human Services. Available on:

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