Normal White Blood Cell (WBC) Count

If you've had your blood tested, you may have seen the letters W-B-C among your results. This is your white blood cell (WBC) count. The test can help doctors figure out if something is going on inside your body. It can also help people living with chronic illnesses manage their conditions.

Read on to learn more about the (WBC) count, its ranges, and why your doctor might order one of these tests.

(WBC) Count Fast Facts

Top things to know about the WBC count include:

  • White blood cells fight infection and inflammation in the body.
  • A normal (WBC) count is not an exact number.
  • (WBC) count results are divided into three ranges, low, normal, and high.
  • Doctors use (WBC) count and other test results to monitor the status of a disease or condition.
white blood cell count ranges

Verywell/Nez Riaz

Purpose of the Test

Your white blood cells make up less than 1% of all your blood cells.Still, they play a vital role in keeping you healthy. They're made in your bone marrow and are part of your immune system.

White blood cells ease inflammation and fight infections. They also protect your body from damage due to toxins like air pollution.

Your doctor might order a (WBC) count if you have the following symptoms:

A (WBC) count measures the number of white blood cells in your blood. There are five different types of white blood cells:

  • Neutrophils fight bacteria and fungal infections. They usually make up 50% to 75% of all your white blood cells.
  • Lymphocytes fight infections, make antibodies and destroy tumors. They are in both your blood and lymph tissue.
  • Monocytes remove damaged or dead cells. They travel into tissues like your lungs and liver and become another kind of cell that eases inflammation.
  • Eosinophils fight infections caused by parasites. They also respond to allergic reactions and inflammation.
  • Basophils release a chemical called histamine during an allergic response. This triggers symptoms like a runny nose or watery eyes.

If you see amounts for these five cells on your results, your doctor ordered a (WBC) count differential test. "Diff" tests can tell doctors which type of white blood cell is high or low. This can help them solve what's causing your symptoms.

(WBC) counts are often part of a more extensive test called a complete blood cell (CBC) count Doctors order (CBC) counts if you're getting a physical or if they suspect you have an infection or a specific condition. Another reason might be to make sure your medication level isn't too strong.  

How the Test Is Done

Getting your (WBC) count requires a simple blood draw. A healthcare practitioner will use a thin needle to collect blood from one of your veins. You usually get the results back from the lab in a few days.

Your doctor might tell you to stop taking your medicine, vitamins, or supplements a few days before your test. That's to make sure they don't affect your results.

Reference (Normal) Range

The (WBC) count is also known as a leukocyte or white count.There's not a set number that defines a "normal" (WBC) count. Results are reported in ranges of low, normal, or high.

Labs can differ on their measurements and how they define a high or a low (WBC) count. (WBC) counts also vary from person to person. Factors like your age, sex, race, and the time of day your blood was drawn can affect your results.


For example, researchers in China studied blood samples of 46,879 individuals. The participants ranged from high schoolers to retired workers. They found that levels of some white blood cells change in women after they undergo menopause.

Another large study conducted by UK researchers suggested timing matters. The study showed (WBC) results could differ by 24% depending on whether your test was in the morning or at the end of the day.

Most test results provide a reference for what the lab considers high, low, and normal ranges for someone of your age and sex. The figure below is an example of a range table. The units are in cells per cubic millimeter (mm3).

 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 > 10,000 white blood cells per mm3

Recap

White blood cells fight infection and inflammation in the body. (WBC) count results are divided into three ranges, low, normal, and high.

Interpreting Results

The (WBC) count isn't specific enough to diagnose any particular disease.However, it can provide information to help your doctor figure out what might be going on inside you.

If your (WBC) count is high, it's called leukocytosis. The condition could be caused by:

  • Infections
  • Inflammation
  • Leukemia
  • Burns
  • Use of steroids
  • Cigarette smoking
  • Pregnancy

If your (WBC) count is low, you have leukopenia. The condition could be due to:

Abnormal (WBC) Count Due to Medications

Many prescription and over-the-counter medicines can cause an abnormal (WBC) count. That's why it's essential to go over your medical history thoroughly with your doctor. Make sure to list all of the drugs you're taking.

A common side effect of many medicines is that they can lower your (WBC) count. The classes of drugs that can do this include chemotherapy, anti-seizure, and antibiotics.

Some medicines can raise your (WBC) count. Names of common drugs that can do this include:

  • Albuterol is a drug that widens airways. It's used to treat asthma and other breathing problems.
  • Lithium is a drug that stabilizes moods. It's used to treat manic depression and bipolar disorder.
  • Heparin is a drug that thins the blood. It's used to prevent blood clots.

Other Tests Your Doctor May Order

If your (WBC) count is abnormal, your doctor may order more tests depending on your medical history and symptoms. These could include tests to see if you have:

  • An infection: Doctors may order a strep test or urine culture, for example, if they think you have a bacterial infection. If they believe you have a virus, they might order a test to see if you have mononucleosis or Epstein-Barr virus.
  • An inflammation problem: Doctors may order a c-reactive protein test (CRP). CRP levels increase if you have inflammation anywhere in your body.
  • An autoimmune disorder: Doctors might order an antinuclear antibody test (ANA). This test looks for autoantibodies, which attack healthy cells and tissue.
  • An allergy: Doctors may order a skin or food allergy test.
  • Leukemia: Doctors may order more blood and bone marrow tests.

(WBC) Count as a Biomarker

If your (WBC) count comes back abnormal, it's important to follow through with your doctor and determine the cause. Studies have shown that high (WBC) counts can be a red flag for a severe health problem.

Researchers did blood tests on 74,375 women who had gone through menopause. They repeated the tests three years later and followed the women for 16 years. The researchers found that high (WBC) counts were associated with an increased risk of death, especially from heart disease.

They believe this is due to inflammation occurring within the body. Other studies have linked getting more than one high (WBC) count to an increased risk of dying from stroke and cancer.

(WBC) Count and Race

Several studies have shown that race can also be a factor in (WBC) count results. In one large study, researchers examined blood samples of 7,157 men and women.

The researchers found that Black participants had significantly lower (WBC) counts than non-Black participants in the study.

The researchers point out that differences in (WBC) count cause treatment delays for Black patients. One study suggested that up to 70% of clinical decisions are based on information from lab results.How much doctors use labs could depend on their specialties. Other researchers warn using the current standards for (WBC) count could cause Black patients to be excluded from clinical trials.

Summary

White blood cells fight infection and inflammation. A white blood cell (WBC) count measures the number of white blood cells in your blood. The test isn't specific enough to diagnose a particular disease or condition. Still, it can provide valuable clues as to what might be causing your symptoms. Results can vary depending on the lab your doctor used and how it defines a low, normal, or high range.

Many factors, including infection, inflammation, and conditions like a blood or bone marrow disorder, can cause an abnormal (WBC) count. Tell your doctor about all the medications you're taking because many drugs can also affect your results.

It's important to discuss your (WBC) count results with your doctor to understand what they could mean.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kabat GC, Kim MY, Manson JE, Lessin L, Lin J, Wassertheil-Smoller S, et al. White blood cell count and total and cause-specific mortality in the women's health initiative. Am J Epidemiol. 2017;186(1):63-72. doi:10.1093/aje/kww226

  2. Memorial Sloan Kettering Cancer Center.Facts about blood and cells. Last updated August 15, 2019.

  3. Hung SC, Cheng HY, Yang CC, Lin CI, Ho CK, Lee WH, et al. The association of white blood cells and air pollutants—A population-based study. International Journal of Environmental Research and Public Health. 2021, 18, 2370. doi: 10.3390/ijerph18052370

  4. Cleveland Clinic. High white blood cell count. Last reviewed January 12, 2018.

  5. National Cancer Institute. Dictionary of cancer terms.

  6. Lab Tests Online.White blood cell count. Last modified June 18, 2021.

  7. Cleveland Clinic. High white blood cell count. Last reviewed January 12, 2018.

  8. Coates S, Wang D, Pierscionek T, Fernandes S, Djumanov D, Lorch U, et al. Time- and race-specific haematological reference intervals for healthy volunteer trials: a retrospective analysis of pooled data from multiple phase i trials. Front Pharmacol. 2020;0. doi.org/10.3389/fphar.2020.00314

  9. Riley LK, Rupert J. Evaluation of Patients with Leukocytosis. Am Fam Physician. 2015;92(11):1004-11.

  10. Shuman M, Lee Demler T, Trigoboff E, Opler LA. Hematologic impact of antibiotic administration on patients taking clozapine. Innov Clin Neurosci. 2012;9(11-12):18-30.

  11. University of Florida Health. WBC count. Last updated January 19, 2021.

  12. Shankar A, Wang JJ, Rochtchina E, Yu MC, Kefford R, Mitchell P, Association between circulating white blood cell count and cancer mortality: a population-based cohort study. Arch Intern Med. 2006;166(2):188-194. doi:10.1001/archinte.166.2.188

  13. Beastall GH. Adding value to laboratory medicine: a professional responsibility. Clin Chem Lab Med. 2013;51(1):221-227. doi::10.1515/cclm-2012-0630

Additional Reading