The short answer
Your white blood cell count adds up all the cells that fight infection. Labcorp’s normal range is 3.4 to 10.8 ×10³/µL, and a high count is usually your body reacting to something, such as an infection, stress or smoking.1,2
Check your result
Type the number from your report. It stays on this page.
- Low Under 3.0
- Slightly low 3.0 to 3.3
- Normal 3.4 to 10.8
- High 10.9 to 30.0
- Very high 30.1 or more
Enter your result to see what it means and what to do next.
Got a result from another lab? Ask Picardo about it. The app explains your results, and a physician can follow up.
Green is Labcorp’s normal range.1 The 3.0 line is the bottom of the normal range for US adults with the Duffy-null blood type,5 and 30 is a warning sign for a blood cancer in a family-medicine review.2 The bar isn’t to scale.
Low: look at your neutrophil count
This is below the normal range even for US adults with the Duffy-null blood type.5 A low total usually means low neutrophils, the cells that fight bacteria, so the neutrophil count on the same report matters most.3 Common causes include infections, medicines and low B12, folate or copper.4
See a clinician within a week or two, or today if your neutrophil count is under 0.5. Under 0.5 with a fever is an emergency: go to an emergency department now.4 A fever here means 101 °F (38.3 °C) or higher once, or 100.4 °F (38.0 °C) or higher for an hour.9
- 1 Look at your neutrophil and lymphocyte counts to see which type is low.3
- 2 Repeat the count with B12 and folate.4
- 3 Bring a list of your medicines, since many can lower white cells.4
Slightly low, and often harmless
Labcorp flags this, but it’s inside the normal range for US adults with the Duffy-null blood type, which starts at 3.0.1,5 Duffy-null is common in people with African, Caribbean or Middle Eastern ancestry, and its lower counts don’t come with more infections.4
Usually nothing to worry about, especially if your neutrophil count is normal and you feel well.
- 1 Check the neutrophil count on the same report. It usually explains a low total.3
- 2 Compare with past results. Your counts tend to stay near your own steady level for years, so a count that has always run low means less than a new drop.8
- 3 Repeat the count in a few weeks if it’s new, or at your next checkup if it isn’t.
In the healthy range
Your total is normal.1 One type of white cell can still be off when the total isn’t, so it’s worth a glance at the neutrophil and lymphocyte counts too.3
Nothing to worry about.
High: usually a reaction to something
Counts in this range are usually reactive. Your body is responding to an infection, inflammation, stress, smoking, extra weight, pregnancy or a medicine such as steroids.2 Most often, the extra cells are neutrophils.2
Not urgent if you feel well. See a clinician within a few days if you have a fever or other signs of infection, or weight loss, night sweats, easy bruising or swollen glands.2
- 1 Look at which type is high: neutrophils point to infection, inflammation or stress, and lymphocytes often to a virus.2
- 2 Repeat the count in a few weeks, once any infection has passed.2
- 3 If there’s no obvious cause, add CRP to see whether inflammation is behind it.2
Very high: see a clinician promptly
A count over 30 is one of the signs that point to a blood cancer such as leukemia, though a severe infection can push it this high too.2 Over 100, it’s almost always a leukemia or a related bone marrow disorder.2
See a clinician within a day or two. Go the same day if it’s over 100, or if you have a fever, bleeding or feel very unwell.
What is a normal white blood cell count?
Labcorp’s range is 3.4 to 10.8 ×10³/µL, one range for every adult.1 Many clinicians call a count over 11.0 high, and in late pregnancy the normal range runs up to about 13.2 What a result outside the range means depends on how far out it is, and on which type of white cell is behind it:
Low: look at your neutrophil count
This is below the normal range even for US adults with the Duffy-null blood type.5 A low total usually means low neutrophils, the cells that fight bacteria, so the neutrophil count on the same report matters most.3 Common causes include infections, medicines and low B12, folate or copper.4
See a clinician within a week or two, or today if your neutrophil count is under 0.5. Under 0.5 with a fever is an emergency: go to an emergency department now.4 A fever here means 101 °F (38.3 °C) or higher once, or 100.4 °F (38.0 °C) or higher for an hour.9
Slightly low, and often harmless
Labcorp flags this, but it’s inside the normal range for US adults with the Duffy-null blood type, which starts at 3.0.1,5 Duffy-null is common in people with African, Caribbean or Middle Eastern ancestry, and its lower counts don’t come with more infections.4
Usually nothing to worry about, especially if your neutrophil count is normal and you feel well.
- 1 Check the neutrophil count on the same report. It usually explains a low total.3
- 2 Compare with past results. Your counts tend to stay near your own steady level for years, so a count that has always run low means less than a new drop.8
- 3 Repeat the count in a few weeks if it’s new, or at your next checkup if it isn’t.
In the healthy range
Your total is normal.1 One type of white cell can still be off when the total isn’t, so it’s worth a glance at the neutrophil and lymphocyte counts too.3
Nothing to worry about.
High: usually a reaction to something
Counts in this range are usually reactive. Your body is responding to an infection, inflammation, stress, smoking, extra weight, pregnancy or a medicine such as steroids.2 Most often, the extra cells are neutrophils.2
Not urgent if you feel well. See a clinician within a few days if you have a fever or other signs of infection, or weight loss, night sweats, easy bruising or swollen glands.2
Very high: see a clinician promptly
A count over 30 is one of the signs that point to a blood cancer such as leukemia, though a severe infection can push it this high too.2 Over 100, it’s almost always a leukemia or a related bone marrow disorder.2
See a clinician within a day or two. Go the same day if it’s over 100, or if you have a fever, bleeding or feel very unwell.
What is a white blood cell count?
Think of the total as the size of your immune army and the breakdown under it as the troops. A total can look normal while one type is low, so the breakdown often tells you more.3
White blood cells fight infection. Your report gives the total, then splits it into five types, each with its own range:1
| Type | Labcorp range (×10³/µL) | Often raised by |
|---|---|---|
| Neutrophils | 1.4 to 7.0 | Infection, inflammation, stress, smoking, steroids |
| Lymphocytes | 0.7 to 3.1 | Viral infections, some leukemias |
| Monocytes | 0.1 to 0.9 | Autoimmune disease, some infections such as tuberculosis |
| Eosinophils | 0.0 to 0.4 | Allergies and asthma, reactions to medicines, parasites |
| Basophils | 0.0 to 0.2 | Allergies, some leukemias |
Ranges from Labcorp’s report;1 causes from a family-medicine review.2
What causes a high white blood cell count?
Most high counts are your body reacting to something, and the extra cells are usually neutrophils.2 An infection is the classic reason. But stress, smoking, extra weight, pregnancy and steroids raise the count too, and it can double within hours of surgery or hard exercise.2 The neutrophil count guide lists the causes in full.
Less often, it’s a leukemia or another bone marrow disorder. Chronic leukemias are most often found this way, on a routine blood count in someone without symptoms.2 Clues that point that way include a count over 30, low hemoglobin or abnormal platelets, and weight loss, night sweats, bruising or swollen glands.2
What causes a low white blood cell count?
A low total usually means low neutrophils.3 Causes include:
- The Duffy-null blood type, common in people with African, Caribbean or Middle Eastern ancestry. It lowers the count without raising the risk of infection.4,5
- Infections4
- Medicines, from chemotherapy to drugs that cause an unpredictable reaction in some people4
- Low vitamin B12, folate or copper4
- Autoimmune conditions4
- Less often, a bone marrow problem such as leukemia4
Low lymphocytes can pull the total down too. But lymphocytes make up only 20% to 40% of white cells, so a low lymphocyte count can hide inside a normal total.3 The lymphocyte count guide covers those.
Does a high-normal white blood cell count matter?
Over decades, it goes with a moderately higher risk of heart disease. In a pooled analysis of long-term studies, people whose counts averaged 8.4 ×10³/µL had about 1.4 times the risk of coronary heart disease of people averaging 5.6, though both are in the normal range.6 In a Baltimore study that followed adults for decades, those who started above 6.0 had higher death rates than those who started between 3.5 and 6.0, even after allowing for age, smoking and weight.7
These are observational links, so they can’t show the white cells themselves cause harm. Smoking and extra weight, for example, raise the count too.2 If yours runs high-normal and you smoke, that’s one more reason to stop.
Who should get a white blood cell count?
It comes with a complete blood count, which many people get at a checkup. It’s worth checking if any of these apply to you:
- You have symptoms that can come with a blood disorder: unexplained tiredness, fevers, night sweats, weight loss, easy bruising or swollen glands.2
- You take a medicine that can lower white cells, such as chemotherapy.4
- Your count has been off before. Your counts stay near your own steady level for years, so tracking them shows what’s normal for you.8
How to get a white blood cell count test, and what it costs
It comes from the complete blood count, which costs $3.75 through Picardo.
Complete blood count
The test this number comes from.
- Results in 2 to 3 days, in the app
- Physician follow-up if you want one
- Free Labcorp draw, or $75 at home
- No other fees. HSA and FSA eligible.
It’s also part of the Base Core Annual – Men, Base Core Annual – Women, Heart Health, Brain Health Screening, Pregnancy, Postpartum, Fertility, Thyroid & Autoimmunity and Celiac / GI panels, if you’d rather test more at once.
Already have a result? Ask Picardo about itQuestions people ask
Can stress raise your white blood cell count?
Yes. Physical stress, such as surgery or hard exercise, and emotional stress, such as a panic attack, can raise it, and the count can double within hours.2 After a knee or hip replacement, for example, it rose by about 2.8 ×10³/µL on average.2
Do I need to do anything before the test?
No fasting needed. Hard exercise and acute stress can push the count up for a while, so a test on a calm day gives the clearest reading.2
Is a white blood cell count of 11 high?
It’s just above Labcorp’s 10.8, and right at the line many clinicians use.1,2 If you feel well, the first step is usually a repeat count.2
Does pregnancy raise your white blood cell count?
Yes, gradually. By the third trimester, a normal count runs from about 5.8 to 13.2 ×10³/µL.2
Why do the percentages on my report have no range?
Labcorp lists each type of white cell twice, as a percentage and as an absolute count, and gives a range only for the absolute counts.1 Go by those. A percentage can look odd simply because another type has gone up or down.
Often checked alongside
Test details
- Labcorp test
- Complete Blood Count (CBC) With Differential, Reflex to Peripheral Smear Review, 005009
- LOINC
- 6690-2
- Sample
- Blood
- Fasting
- Not needed
- Typical lab range
- 3.4 to 10.8 ×10³/µL
- Units
- ×10³/µL, which Labcorp prints as x10E3/uL. It’s the same number as ×10⁹/L.
Sources
- 1 Labcorp. CBC with differential/platelet, test 005009: sample patient reports (female, age 46; reported September 15, 2026). Burlington, NC: Labcorp; 2026. Accessed October 28, 2026. files.labcorp.com/testmenu-d8/sample_reports/005009.pdf
- 2 Riley LK, Rupert J. Evaluation of patients with leukocytosis. Am Fam Physician. 2015;92(11):1004–1011. pubmed.ncbi.nlm.nih.gov/26760415/
- 3 Dale DC. Overview of leukopenias. Merck Manual Professional Edition. Reviewed February 2025. Accessed October 28, 2026. www.merckmanuals.com/professional/hematology-and-oncology/leukopenias/overview-of-leukopenias
- 4 Kim MJ, Forlini C, Kremsreiter K. Neutropenia: evaluation and management in the primary care setting. Am Fam Physician. 2025;112(6):618–628. pubmed.ncbi.nlm.nih.gov/41533406/
- 5 Hibbs SP, Chipare I, Halawani AJ, et al. Multinational assessment of absolute neutrophil counts and white blood cell counts among healthy Duffy-null adults. Blood. 2026;147(3):290–298. doi.org/10.1182/blood.2025029359
- 6 Danesh J, Collins R, Appleby P, Peto R. Association of fibrinogen, C-reactive protein, albumin, or leukocyte count with coronary heart disease: meta-analyses of prospective studies. JAMA. 1998;279(18):1477–1482. doi.org/10.1001/jama.279.18.1477
- 7 Ruggiero C, Metter EJ, Cherubini A, et al. White blood cell count and mortality in the Baltimore Longitudinal Study of Aging. J Am Coll Cardiol. 2007;49(18):1841–1850. doi.org/10.1016/j.jacc.2007.01.076
- 8 Foy BH, Petherbridge R, Roth MT, et al. Haematological setpoints are a stable and patient-specific deep phenotype. Nature. 2025;637(8045):430–438. doi.org/10.1038/s41586-024-08264-5
- 9 Taplitz RA, Kennedy EB, Bow EJ, et al. Outpatient management of fever and neutropenia in adults treated for malignancy: American Society of Clinical Oncology and Infectious Diseases Society of America clinical practice guideline update. J Clin Oncol. 2018;36(14):1443–1453. doi.org/10.1200/JCO.2017.77.6211
Updated 28 Oct 2026.
This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.