Neutrophils Blood Test: High & Low Absolute Count

Neutrophils are the most abundant white blood cells in your blood and your body's front-line defense against bacterial infections. They are counted in the differential of a complete blood count (CBC), both as a percentage and — more importantly — as an absolute number, the absolute neutrophil count (ANC). This guide explains the normal range, what a high neutrophil count (neutrophilia) or a low one (neutropenia) means, the causes worth chasing, and what to do. To place them in context, read our guides on white blood cells and the complete blood count.

Key takeaways

• Neutrophils are the most common white blood cells (about 40–75% of white cells) and the first responders to bacterial infection.¹
• What matters most is not the percentage but the absolute neutrophil count (ANC), indicatively ~1.5–7.5 × 10⁹/L in adults — values vary by lab.²¹
• Neutropenia (a low ANC) is usually defined as < 1.5 × 10⁹/L, and is severe below 0.5 (agranulocytosis), with a real infection risk.³¹
• Neutrophilia (a high count) most often goes with bacterial infection, inflammation, stress/exercise, corticosteroids, smoking, and pregnancy — usually harmless.¹
• Duffy-null-associated neutrophil count (formerly "benign ethnic neutropenia," common in people of African ancestry) gives a slightly low ANC without extra infection risk — not a true neutropenia.⁴⁵
• The neutrophil-to-lymphocyte ratio (NLR) is an inflammation marker studied as a prognostic tool in infection, COVID-19, cancer, and cardiovascular disease.⁶⁷

What are neutrophils?

Neutrophils are a type of white blood cell (leukocyte). Made in the bone marrow, they circulate in the blood for only a few hours before migrating into tissues, where they engulf and destroy bacteria and fungi — a process called phagocytosis. They are the main weapon of the innate immune system, the fast-acting arm of immunity that responds without memory.¹

On your report, neutrophils appear in the differential ("diff") alongside lymphocytes, monocytes, eosinophils, and basophils — all subtypes of white blood cells. The lab gives two figures: a percentage (the share of neutrophils among all white cells) and, more usefully, an absolute count in × 10⁹/L (also written as cells/µL, e.g. 1.5 × 10⁹/L = 1,500 cells/µL). That absolute figure is the ANC (absolute neutrophil count).

The number that counts is the ANC. A percentage alone can mislead: if your total white cell count is low, "80% neutrophils" does not mean many neutrophils. Read the absolute count (ANC) first, in × 10⁹/L.¹

Why the test is done

Neutrophils are almost never measured alone — they are part of the CBC with differential, one of the most common blood tests. Your clinician looks at them to:²³

• find or follow an infection, especially a bacterial one (neutrophils rise);
• assess inflammation, often alongside CRP and the ESR (sed rate);
• monitor chemotherapy or any drug known to lower neutrophils (the ANC governs how safely treatment can proceed);
• work up unexplained fatigue, recurrent infections, mouth ulcers, or fever;
• screen for bone marrow disease when several cell lines are abnormal.

It is a valuable screening marker: it points the way, but it is always read together with the rest of the CBC and your clinical picture.

Do you need to fast?

No. The CBC with differential does not require fasting — you can eat normally beforehand. Be aware, though, that strenuous exercise, stress, smoking, or a heavy meal just before the draw can transiently raise neutrophils. If your blood draw also includes tests that do require fasting (glucose, lipid panel), follow the strictest instruction on your order (see Do you need to fast before a blood test?).²

Normal ranges

Below are indicative adult reference values for neutrophils, given as an absolute count and a percentage. They vary by lab, age, ancestry, and context — always compare against the range printed on your report.

Units: the count is reported in × 10⁹/L (the same as 1,000 cells/µL, or "per mm³"). The percentage helps, but the absolute count (ANC) drives decisions. Thresholds differ from lab to lab, and ancestry can shift the lower limit (see below). Only your clinician can interpret the number in your context.¹²

Understanding your results

High neutrophils (neutrophilia)

A high neutrophil count (> ~7.5 × 10⁹/L) is usually reactive and not serious. Common causes:¹³

• a bacterial infection (the most frequent cause);
• inflammation or tissue injury (trauma, burn, surgery, heart attack);
• physiological stress: intense exercise, pain, strong emotion, cold, seizures — "marginated" neutrophils are released into the bloodstream within minutes;
• certain medications, above all corticosteroids, but also growth factors (G-CSF) and adrenaline;
• smoking, pregnancy, and the postpartum period;
• more rarely, when counts are very high or immature cells appear in the blood (a "left shift"), a myeloproliferative disorder such as chronic myeloid leukemia — which warrants specialist review.

Do high neutrophils mean cancer? Almost never. A modest neutrophilia points first to infection, inflammation, or stress. It is mainly very high, persistent elevations, or those tied to other CBC abnormalities, that prompt a search for a blood disorder — a rare situation, assessed by your clinician.

Low neutrophils (neutropenia)

A low neutrophil count (< ~1.5 × 10⁹/L) should prompt a search for a cause. The risk of serious infection depends mostly on how deep the drop is: it becomes real below 0.5 × 10⁹/L (agranulocytosis). Main causes:³¹

• a recent viral infection (flu, hepatitis, HIV, EBV) — a common and usually temporary cause;
• medications: chemotherapy first and foremost, but also some antibiotics, antithyroid drugs, anti-seizure medicines, anti-inflammatories, and psychiatric drugs (including clozapine);⁸
• a vitamin B12 or folate deficiency;
• an autoimmune condition (lupus, rheumatoid arthritis);
• hypersplenism (an enlarged spleen that traps cells);
• bone marrow disease (aplasia, leukemia, infiltration) — rarer, often with low red blood cells and platelets too.

Febrile neutropenia — the emergency to know. In someone on chemotherapy, a fever with neutropenia (especially < 0.5 × 10⁹/L) is a medical emergency called febrile neutropenia, requiring prompt evaluation and antibiotics within about an hour of assessment. Any fever during chemotherapy should trigger an immediate call to the care team.⁹¹⁰

Duffy-null neutrophil count (do not confuse it)

Many people of African ancestry (and some of Middle Eastern or Caribbean descent) run a consistently slightly low ANC, often between 1.0 and 1.5 × 10⁹/L, with no increased susceptibility to infection. This is benign ethnic neutropenia, tied to the Duffy-null phenotype (a variant of the ACKR1/DARC gene): the neutrophils are simply distributed differently, and the marrow makes normal numbers.⁴⁵ It is not a disease and needs no treatment or alarming work-up. Experts now recommend calling it the "Duffy-null-associated neutrophil count" rather than neutropenia, and adjusting reference ranges to avoid unnecessary testing.⁵ If this applies to you, tell your clinician — it changes how your number is read.

What affects your neutrophils

Many factors shift the neutrophil count, often transiently: the time of day, exercise, stress, smoking, pregnancy, age, an ongoing infection, ancestry (Duffy status), and — most of all — medications (corticosteroids raise it; chemotherapy and certain drugs lower it). Always mention your medications, a recent infection, or pregnancy: they change the interpretation.¹³

Recent research

According to recent PubMed-indexed publications:

• The neutrophil-to-lymphocyte ratio (NLR), a rising prognostic marker. Calculated by dividing the neutrophil count by the lymphocyte count, the NLR reflects the balance between inflammation and immunity. A normal value sits around 1–2; above 3 it signals inflammation or stress. The NLR is now studied as a prognostic indicator across many settings.⁶ (Zahorec R, Bratisl Lek Listy, 2021 — DOI.)
• NLR, infection, and COVID-19. A high NLR has been linked to more severe disease and higher mortality in infection, sepsis, and COVID-19, and was even folded into some hospital decision aids.⁷ (Buonacera A et al., Int J Mol Sci, 2022 — DOI.)
• NLR and cancer. In many solid tumors, a high pre-treatment NLR is associated with a worse prognosis; it is studied as a simple, low-cost marker alongside other CBC-derived inflammation indices.¹¹ (Yamamoto T et al., Int J Mol Sci, 2021 — DOI.)
• Rethinking "ethnic" neutropenia. Recent work confirms that the lower ANC of Duffy-null individuals carries no extra infection risk, even on drugs long considered risky such as clozapine — sparing patients unnecessary treatment stops and work-ups.⁵⁸

These findings concern diagnosis and research; they do not authorize self-medication and do not replace your physician's advice.

Get your neutrophils interpreted by AI DiagMe

A neutrophil count is never read alone: its meaning depends on the rest of your CBC, your white blood cells, your CRP, your medications, a recent infection, and your context. That cross-reading is what gives the result its real value.

👉 AI DiagMe interprets your lab results — blood, urine, or stool — in plain language, taking your whole profile into account. An informational service that does not provide a diagnosis and complements, never replaces, your physician.

Frequently asked questions

Bottom line

Neutrophils are the most abundant white blood cells and your first line of defense against bacteria. Keep in mind that the absolute count (ANC) is what counts, with a normal range around ~1.5–7.5 × 10⁹/L (lab-dependent). A high count points mostly to infection, inflammation, or stress; a low count (neutropenia) calls for finding a viral, drug-related, or nutritional cause, with real infection risk below 0.5 × 10⁹/L. The Duffy-null neutrophil count is a harmless special case worth knowing. No value is read alone — it's your whole set of markers and your context that counts, which is what AI DiagMe provides, alongside your physician.

Sources

Official sources and peer-reviewed publications (PubMed) used for this guide: