Neutrophils
Most common type of white blood cell, mainly involved in fighting bacterial infections
Also known as
Definition
Neutrophils are the most common of the five types of white blood cells (leukocytes). They are made in the bone marrow and are the body's main defense when bacteria, viruses or other germs enter; above all, they target bacterial infections. The blood differential reports them as a share of all white blood cells, often split into young band cells and segmented cells, and frequently also as an absolute number.
| Parameter | Value |
|---|---|
| Unit | % of white blood cells; absolute as /µl or /nl (= 10⁹/l) |
| Reference Range | Typical for adults: about 40–60 % of white blood cells (MedlinePlus). The German Society of Hematology and Medical Oncology (DGHO) gives an example normal range of 40–70 % segmented and 3–5 % band neutrophils. Labs differ and often report an absolute number as well; the range printed on your own report is what counts. Discuss any deviation with your doctor. |
Agree on your personal target range with your doctor.
1/nl equals 1,000/µl or 1 × 10⁹/l. The absolute number is the percentage multiplied by the white blood cell count.
↓ What a low value means
A reduced count is called neutropenia. Because neutrophils are the main defense against infection, the risk of infection rises. A low share can be linked to flu or other viral infections, a severe bacterial infection spread throughout the body (sepsis), chemotherapy, radiation therapy or radiation exposure, and aplastic anemia. After chemotherapy, neutropenia often occurs between day 7 and day 12. In addition, the percentage drops arithmetically when another type of white blood cell rises sharply. Discuss any deviation with your doctor.
↑ What a high value means
A raised count is called neutrophilia. A higher share can be linked to acute infections, inflammation, acute stress, injury and smoking, and also to rheumatoid arthritis, rheumatic fever, gout, thyroid inflammation or eclampsia in pregnancy, and less often to acute or chronic leukemia and other myeloproliferative diseases of the bone marrow. An abnormal value does not always mean a condition that needs treatment; your doctor clarifies the cause, often with further tests.
When to test
Neutrophils are measured as part of the blood differential, often at routine check-ups. The test is ordered specifically to clarify symptoms such as unusual tiredness, weakness or unexplained bruising or an abnormal white blood cell count, to monitor known blood disorders and to detect neutropenia during chemotherapy. No special preparation is needed.
Frequently asked questions
What do band and segmented mean? +
Band neutrophils are a young form of these cells; segmented neutrophils make up most of the neutrophils in the blood. The blood differential often lists them separately; the DGHO gives example normal ranges of 3–5 % band and 40–70 % segmented neutrophils.
Why does my report show a percentage and an absolute number? +
The percentage is the share of neutrophils among all white blood cells; the absolute number results from multiplying it by the white blood cell count. If another cell type rises sharply, the percentage of neutrophils falls without their absolute number necessarily changing.
What is neutropenia? +
Neutropenia means a lower number of neutrophils than usual. Because these cells are the main defense against infection, the risk of infections rises. It often occurs after chemotherapy; whether and how often the blood count is checked then is decided by your doctor.
Can stress or smoking affect the value? +
Yes. Acute stress, injury and smoking can raise the share of neutrophils. Alcohol can also affect blood differential results. A single abnormal value is therefore not a finding on its own; your doctor takes symptoms, medical history and other blood values into account.
Neutrophils
Sources
- MedlinePlus, National Library of Medicine: Blood Differential
- MedlinePlus, National Library of Medicine: Blood differential test
- MedlinePlus, National Library of Medicine: White Blood Count (WBC)
- DGHO (German Society of Hematology and Medical Oncology), Onkopedia guideline: Hämatologische Diagnostik (2025, in German)
- Centers for Disease Control and Prevention (CDC): Neutropenia and Risk for Infection
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.