Normal White Blood Cell (WBC) Count

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

Test tubes in laboratory
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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 doctors will measure to better understand what might be going on inside the body during 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. 

Fast Facts About the WBC Count

  • White blood cells fight infection and inflammation in the body
  • A high white blood cell could indicate that there's an infection or inflammation in the body
  • A normal WBC count is a range rather than an exact number
  • The WBC count result is used along with other test results to monitor the status of a disease or condition

What Is a WBC Count Test?

Blood contains several different types of cells. White blood cells are one of the types of cells that are found in the blood. These specialized cells are one part of the body's immune response.

White blood cells are created inside the bone marrow, the spongy tissue inside bones. The number of white cells in the blood, which is called a white blood cell count, is actually a range that varies from person to person. There is, however, an estimate as to what is a typical white blood cell count and what is too high or too low.

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 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 < 4,000 white blood cells per mm3*
 Approximate Normal Range 4,500-10,000 white blood cells per mm3
 Approximate High Range  > 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:

Other Causes of an Abnormal WBC Count in IBD

A WBC count could be out of the normal range due to some medications that are used to treat IBD. In particular, corticosteroids such as prednisone may cause an increase in white blood cells. Some medications that treat IBD, such as 6-MP and Imuran, may cause the WBC count to be lower than normal. A gastroenterologist can help put a WBC count into perspective when these drugs are being used to treat IBD.

Does an Out of Range WBC Count Have Symptoms?

A high WBC count could mean that there's inflammation or an infection somewhere in the body. In some cases, it might be clear that it's related to an existing disease or condition, in which case, the symptoms of that disease might be present. In some cases, there could be symptoms associated with a low WBC count. Those symptoms might be:

  • Body aches or pains
  • Chills
  • Fever
  • Headache

A Word From Verywell

A WBC count isn't specific in diagnosing a disease or condition. However, in the case of someone who has IBD, a high WBC count could mean that the IBD is causing inflammation. It's also possible that a separate condition is causing the abnormal WBC count, which is why other tests might need to be done to determine what's happening.

Taken altogether, the results of a WBC count, any physical symptoms, and the results of other tests will help a physician to determine what is going on in the body. It's important to discuss the results of the WBC count with a physician in order to understand what it could mean.

Sources:

Vermeire S, Van Assche G, Rutgeerts P. "Laboratory markers in IBD: useful, magic, or unnecessary toys?" Gut. 2006 Mar; 55: 426–431. 

Wilkins T, Jarvis K, Patel J. "Diagnosis and Management of Crohn's Disease." Am Fam Physician. 2011 Dec 15;84:1365-1375.

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