White Blood Cell (WBC) Count

A Normal White Blood Cell Count Can Vary From Person To Person

Test tubes in laboratory
Blood tests are commonly done to monitor many different diseases and conditions. The white blood cell count can help a physician determine if there is inflammation in the body. Rubberball/Nicole Hill/Brand X Pictures/Getty Images

Learning what is—and what isn't—a normal white blood cell count is important for people who have chronic health conditions. The white blood cell (WBC) count is an important tool that your doctors will use in a variety of health situations. For people with IBD, the WBC count can be a sign that the inflammation associated with IBD is either increasing or decreasing. As the WBC count goes up, it could mean inflammation is happening somewhere in the body.


What Is A White Blood Cell Count Test?

White blood cells are one type of cell that are found in the blood. These specialized cells are just a part of the body's immune response. White blood cells are created inside the bone marrow, the spongy tissue inside bones.  A normal white blood cell count is a range that varies from person to person. A high WBC count is one sign that there is an inflammatory disease or an inflammatory process taking place somewhere in the body.

There are several different conditions that could cause a higher than normal or a lower than normal WBC count, but it is important to keep in mind that this test is not specific enough to diagnose any particular disease. In some cases, although not always, people who have IBD and are experiencing the associated inflammation in their intestines may be found to have a higher than typical WBC count. The body is using the white blood cells to fight the inflammation, and that is what causes the high WBC count.

Reference Range (Normal Range) For A WBC Count

The WBC count is also sometimes known as a leukocyte count or white count. It is often done as part of a bigger complex of blood tests called a complete blood cell (CBC) count. A WBC count is the number of white blood cells per volume of blood. Be advised, however, that there is no one number that defines a "normal" or a typical WBC count.

The count may be expressed in one of several different types of units because there is variation depending on which unit of measurement a particular lab uses. Different labs will also have their own definition of what constitutes a "high" or a "low" WBC count.

What this all boils down to is that while a table of WBC counts is included below for reference, the numbers are an example of only one approximation of how a normal range might be defined. In addition, a typical WBC count can also vary from person to person: one person's version of "normal" might not be the same as another person's normal. Physicians may compare blood test results to previous blood test results, especially if a "baseline" number exists for a double-check. Ask your physician if you have specific questions about your WBC count numbers or about any blood test results.

 Example White Blood Cell (WBC) Count Reference Ranges
 Approximate Low Range Less than 4,000 white blood cells per mm3
 Approximate Normal Range 4,500-10,000 white blood cells per mm3
 Approximate High Range  More than 11,000 white blood cells per mm3
 mm3, cubic millimeter

What Is WBC Used For?

The WBC count is not actually an indicator of any specific disease; it can't tell your doctor if you have or don't have a particular condition.

Rather, it is used as an important piece of information that a physician can use to help monitor or assess the course of a disease or condition. Leukocytosis is present at an elevated WBC count; leukopenia is a decreased WBC count. 

A higher than typical WBC count (leukocytosis) could be associated with:

  • Allergy
  • Bacterial infection
  • Inflammatory disease
  • Leukemia
  • Malignancy
  • Trauma

A lower than typical WBC count (leukopenia) could be associated with:

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