The short answer
Neutrophils are the white cells that fight bacteria. A low count is the usual worry, but many healthy people run low for a harmless reason: the Duffy-null blood type, which about two in three Black Americans have.2,4
- A healthy range
- 1.4 to 7.0 ×10³/µL at Labcorp.1 If you’re Duffy-null, about 1.2 to 5.4 is normal.4,5
- If yours is low
- A mildly low count is often normal for Duffy-null people, and for everyone a repeat comes first.2,4 Under 0.5 with a fever is an emergency.3
- If yours is high
- It’s usually your body reacting to something, such as an infection, stress, smoking or steroids.6
Check your result
Type the number from your report. It stays on this page.
- Severe Under 0.5
- Moderate 0.5 to 0.9
- Mildly low 1.0 to 1.3
- Normal 1.4 to 7.0
- High 7.1 or more
- Severe Under 0.5
- Moderate 0.5 to 0.9
- Mildly low 1.0 to 1.1
- Normal if Duffy-null 1.2 to 1.3
- Normal 1.4 to 7.0
- High 7.1 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, extended down to about 1.2 if you’re Duffy-null.1,4 The 0.5 and 1.0 lines are the usual cutoffs for severe and moderate neutropenia.2 The bar isn’t to scale.
Severely low: call a clinician today
This is severe neutropenia. Below 0.5, bacteria that normally live harmlessly in your mouth and gut can cause infections, and the usual signs of infection can be muted, so a fever may be the only clue.2
Call a clinician today, even if you feel well. With a fever, it’s an emergency: go to an emergency department now. A fever here means 101 °F (38.3 °C) or higher once, or 100.4 °F (38.0 °C) or higher for an hour.3
- 1 Take your temperature if you feel unwell, and don’t wait out a fever or chills.2,3
- 2 Tell the clinician every medicine and supplement you take. Medicines are one of the most common causes.2
- 3 Expect a repeat count and tests for the cause. If no cause is clear, that can include a bone marrow test.2
Moderately low: see a clinician this week
This is moderate neutropenia, and it’s below the US range for Duffy-null adults too.2,4 Your risk of infection is higher than normal, though not as high as below 0.5.2
See a clinician this week. If you get a fever, get care the same day.2
- 1 List every medicine and supplement you’ve started in the past few months.2
- 2 Repeat the count with B12 and folate. Low levels of either can cause it.2,3
- 3 If you know you’re Duffy-null, say so. Some medicines, such as clozapine, use lower limits for you.7
Mildly low: repeat it before anything else
This is mild neutropenia by the usual definition.2 It’s often normal for Duffy-null people: their range starts at about 1.2, and the clozapine label treats 1.0 or more as normal for them.4,7 And a single count can be misleading, because activity, stress, infections and medicines all shift it.2
Not urgent. A repeat and a look at the trend come first. For healthy Duffy-null people with a lasting mild count, a primary care review advises against extensive testing.3
- 1 Repeat the count in a few weeks, when you’re well. Viral illnesses can lower it for days.2
- 2 Look at your past results. A count that has always run this low fits a Duffy-null pattern, which a Duffy blood-group test can confirm.3,4
- 3 If it stays low and you’re not Duffy-null, check B12 and folate and go over your medicines with a clinician.2
Flagged low, but normal if you’re Duffy-null
Labcorp flags this because it uses one range for everyone.1 In healthy Duffy-null adults, the normal range starts at about 1.2, so this is normal for you.4,5
Nothing to worry about. A lower count from being Duffy-null doesn’t raise your risk of infection.7
In the healthy range
You have a normal number of the white cells that fight bacteria.1,2
Nothing to worry about.
High: usually your body reacting to something
Most high counts are a reaction to an infection, inflammation, physical or emotional stress, smoking or a medicine such as steroids.6 Less often, a bone marrow disorder is the cause.6
Not urgent if you feel well. See a clinician within a few days if you have a fever or other signs of infection, or if weight loss, night sweats, easy bruising or swollen glands come with it.6
- 1 Repeat the count in a few weeks, once any infection has passed.6
- 2 If there’s no obvious cause, add CRP to see whether inflammation is behind it.6
- 3 If your hemoglobin or platelets are also off, see a clinician: changes in more than one count point to the bone marrow.6
What is a normal neutrophil count?
Labcorp uses one range for everyone, 1.4 to 7.0 ×10³/µL. Your report lists neutrophils twice: use the absolute count, “Neutrophils (Absolute)”, because the percentage has no range.1 Below the range, clinicians grade a low count by how much it raises the risk of infection, starting from 1.5:2
Severely low: call a clinician today
This is severe neutropenia. Below 0.5, bacteria that normally live harmlessly in your mouth and gut can cause infections, and the usual signs of infection can be muted, so a fever may be the only clue.2
Call a clinician today, even if you feel well. With a fever, it’s an emergency: go to an emergency department now. A fever here means 101 °F (38.3 °C) or higher once, or 100.4 °F (38.0 °C) or higher for an hour.3
- 1 Take your temperature if you feel unwell, and don’t wait out a fever or chills.2,3
- 2 Tell the clinician every medicine and supplement you take. Medicines are one of the most common causes.2
- 3 Expect a repeat count and tests for the cause. If no cause is clear, that can include a bone marrow test.2
Moderately low: see a clinician this week
This is moderate neutropenia, and it’s below the US range for Duffy-null adults too.2,4 Your risk of infection is higher than normal, though not as high as below 0.5.2
See a clinician this week. If you get a fever, get care the same day.2
Mildly low: repeat it before anything else
This is mild neutropenia by the usual definition.2 It’s often normal for Duffy-null people: their range starts at about 1.2, and the clozapine label treats 1.0 or more as normal for them.4,7 And a single count can be misleading, because activity, stress, infections and medicines all shift it.2
Not urgent. A repeat and a look at the trend come first. For healthy Duffy-null people with a lasting mild count, a primary care review advises against extensive testing.3
- 1 Repeat the count in a few weeks, when you’re well. Viral illnesses can lower it for days.2
- 2 Look at your past results. A count that has always run this low fits a Duffy-null pattern, which a Duffy blood-group test can confirm.3,4
- 3 If it stays low and you’re not Duffy-null, check B12 and folate and go over your medicines with a clinician.2
Flagged low, but normal if you’re Duffy-null
Labcorp flags this because it uses one range for everyone.1 In healthy Duffy-null adults, the normal range starts at about 1.2, so this is normal for you.4,5
Nothing to worry about. A lower count from being Duffy-null doesn’t raise your risk of infection.7
In the healthy range
You have a normal number of the white cells that fight bacteria.1,2
Nothing to worry about.
High: usually your body reacting to something
Most high counts are a reaction to an infection, inflammation, physical or emotional stress, smoking or a medicine such as steroids.6 Less often, a bone marrow disorder is the cause.6
Not urgent if you feel well. See a clinician within a few days if you have a fever or other signs of infection, or if weight loss, night sweats, easy bruising or swollen glands come with it.6
What is a neutrophil count?
Neutrophils are your first responders. Your marrow keeps a reserve of them ready to release, which is why the count can double within hours of an injury, surgery or a hard workout.6
Neutrophils are the body’s main defense against bacteria and fungi.2 The number on your report, “Neutrophils (Absolute)”, is your total white count multiplied by the share that are neutrophils. Clinicians often call it the ANC, for absolute neutrophil count.2
It moves around more than most blood counts. Activity, anxiety, infections and medicines can all shift it from one day to the next, so clinicians often want more than one result before deciding anything.2
Why does being Duffy-null change the range?
Duffy is a protein on the surface of red blood cells. People who are Duffy-null don’t make it, a trait that protects against one kind of malaria.4 It lowers the number of neutrophils circulating in the blood, while the body keeps enough overall.4
A Boston study of 120 healthy Duffy-null adults put their normal range at 1.21 to 5.39 ×10³/µL, against the hospital’s standard range of 1.92 to 7.60.4 A 2026 study of more than 8,000 healthy Duffy-null adults on four continents gave the same US range and found no significant differences between it and the ranges in Namibia, Saudi Arabia and the UK. In its biobank data, Black and non-Black Duffy-null people had similar counts.5 So it’s your Duffy type, not your race, that sets the range. Standard ranges flagged about one in five healthy US Duffy-null adults in that study as neutropenic.5
| Not Duffy-null | Duffy-null | |
|---|---|---|
| Normal range | 1.4 to 7.0 at Labcorp1 | About 1.2 to 5.44,5 |
| Risk of infection | Rises as the count falls below the range2 | Not raised by the lower count7 |
| Clozapine label’s starting limit | 1.5 or more7 | 1.0 or more7 |
Counts in ×10³/µL.
What causes a low neutrophil count?
- Being Duffy-null, which is a normal blood type, not a disease3,4
- A viral infection, which can lower the count for a few days2
- Medicines, one of the most common causes, including some antibiotics, thyroid and seizure medicines, clozapine and chemotherapy2
- Low vitamin B12, folate or copper2,3
- Autoimmune conditions, such as lupus2
- A lasting low count with no cause found, called chronic idiopathic neutropenia. Serious infections are uncommon with it, and it’s much more common in women.2
- Less often, a bone marrow problem such as leukemia, or an enlarged spleen that holds on to white cells2
How to raise a low neutrophil count
The answer depends on the cause, so finding it comes first.3
- Stopping a medicine that’s causing it
If a medicine is the cause, stopping it is the main treatment. When the cause is an immune reaction to the medicine, the low count usually lasts about a week after stopping it. Don’t stop one without talking to the clinician who prescribed it.2
- How much it helps
- A lot
- How sure we are
- Fairly sure
- Treating low B12, folate or copper
If a deficiency is behind it, treating the deficiency treats the low count.3
- How much it helps
- A lot
- How sure we are
- Fairly sure
- G-CSF injections
A medicine that tells your marrow to make more neutrophils. It’s used for severe and inherited neutropenia and after chemotherapy; the benefit for mildly low counts is less clear.2,3
- How much it helps
- A lot
- How sure we are
- Very sure
Vitamins don’t raise the count unless you’re short of one.2 Steroids can push the count up, but they don’t make your marrow produce more neutrophils and generally don’t help a low count.2,6 If you’re Duffy-null, there’s nothing to raise: your count is normal for you.4
What causes a high neutrophil count?
- An infection, especially a bacterial one6
- Physical stress, such as surgery or hard exercise, and emotional stress6
- Smoking6
- Steroids, lithium and beta-agonist asthma medicines6
- Long-term inflammation, such as rheumatoid arthritis or inflammatory bowel disease6
- Pregnancy, extra weight or having had your spleen removed6
- Rarely, a bone marrow disorder such as a leukemia6
Who should know their Duffy type?
It’s worth asking a clinician about a Duffy blood-group test if any of these apply to you:
- Your neutrophil count has run mildly low more than once, and you have African, Caribbean or Middle Eastern ancestry.3
- You take clozapine or might start it. The FDA ended the clozapine REMS, the drug’s special safety program, on June 13, 2025, but still asks prescribers to check neutrophils regularly.8 The label lets Duffy-null people start at 1.0 instead of 1.5.7
- You might join a cancer trial. FDA guidance from July 2026 says trial sponsors may consider relaxing neutrophil limits for Duffy-null patients.9
- You take a medicine that’s dosed or stopped by your count. Standard ranges have led to medicines such as azathioprine being stopped in Duffy-null people whose counts were normal for them.4
How to get a neutrophil 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
How do you find out if you’re Duffy-null?
With a blood typing test that looks for the two Duffy proteins, Fya and Fyb, on your red cells. Duffy-null means you have neither, written Fy(a−b−).4 Ask a clinician for Duffy (Fya and Fyb) typing.
Does being Duffy-null weaken your immune system?
No. Duffy-null people have fewer neutrophils circulating in the blood but enough in the body overall.4 They aren’t at higher risk of infections, or of their counts dropping on clozapine.7
Can a cold or the flu lower your neutrophil count?
Yes. Infections, including viral ones, can lower it. With common childhood viruses, the dip starts in the first day or two of the illness and lasts about 3 to 8 days.2 If your count was low around an illness, recheck once you’re well.
Is a low neutrophil count a sign of cancer?
It’s one possible cause among many. Medicines are one of the most common causes, and infections and being Duffy-null are others.2,4 A marrow problem such as leukemia is also possible, which is why a count that stays low with no clear cause gets a closer look, sometimes with a bone marrow test.2
Why is my neutrophil percentage high when my count is normal?
The percentage depends on your other white cells too. If your lymphocytes are low, neutrophils make up a bigger share without there being more of them. Labcorp sets no range for the percentages, so go by the absolute count.1
Often checked alongside
Test details
- Labcorp test
- Complete Blood Count (CBC) With Differential, Reflex to Peripheral Smear Review, 005009
- LOINC
- 751-8
- Sample
- Blood
- Fasting
- Not needed
- Typical lab range
- 1.4 to 7.0 ×10³/µL, one range for everyone
- 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 Dale DC. Neutropenia. Merck Manual Professional Edition. Reviewed February 2025; updated April 2026. Accessed October 28, 2026. www.merckmanuals.com/professional/hematology-and-oncology/leukopenias/neutropenia
- 3 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/
- 4 Merz LE, Osei MA, Story CM, et al. Development of Duffy null–specific absolute neutrophil count reference ranges. JAMA. 2023;329(23):2088–2089. doi.org/10.1001/jama.2023.7467
- 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 Riley LK, Rupert J. Evaluation of patients with leukocytosis. Am Fam Physician. 2015;92(11):1004–1011. pubmed.ncbi.nlm.nih.gov/26760415/
- 7 HLS Therapeutics. Clozaril (clozapine) tablets: US prescribing information. Revised June 2025. DailyMed. Accessed October 28, 2026. dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=90876802-0e3a-44c9-9ff7-1754dfbe736a
- 8 US Food and Drug Administration. FDA removes risk evaluation and mitigation strategy (REMS) program for the antipsychotic drug clozapine. Drug Safety Communication. August 27, 2025. www.fda.gov/drugs/drug-safety-communications/fda-removes-risk-evaluation-and-mitigation-strategy-rems-program-antipsychotic-drug-clozapine
- 9 US Food and Drug Administration. Cancer clinical trial eligibility criteria: laboratory values. Guidance for industry, IRBs, and clinical investigators. July 2026. www.fda.gov/media/178013/download
Updated 3 Nov 2026.
This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.