Neutrophil count
Neutrophil countFull blood count

Neutrophil count

May 3, 2022

Neutrophil count

What is a neutrophil count?

Neutrophils are the most abundant type of white blood cells. In healthy adults, they typically constitute about 50 to 70 percent of white blood cells and function as the first line of defence against bacteria and other foreign organisms.

Why is this analysis important?

Neutrophils are differentiated from other cells under the microscope by their segmented nucleus and neutral pink stain (hence the name Neutrophil). They respond to inflammation and fight bacteria mainly by their swallowing function (a process called Phagocytosis).

They also release powerful chemicals that help with tissue healing after injury.

What are some of the causes of a high neutrophil count?

A high level of neutrophils in blood ()neutrophilia) is a sign of infection. Neutrophilia can point to a number of underlying conditions and factors, including:

  • Infection, most likely bacterial

  • Noninfectious inflammation

  • Injury

  • Surgery

  • Smoking cigarettes or sniffing tobacco

  • High levels of stress

  • Excessive exercise

  • Steroid use

  • Heart attacks

  • Chronic myeloid leukaemia

What are some of the causes of a low neutrophil count?

Neutropenia is the term for low neutrophil levels. Low neutrophil counts are most often associated with medications but they also can be a sign of other factors or illness, including:

  • Some drugs, including those used in chemotherapy

  • Suppressed immune system

  • Bone marrow failure

  • Aplastic anaemia

  • Febrile neutropenia, which is a medical emergency

  • Congenital disorders, such as Kostmann syndrome and cyclic neutropenia

  • Hepatitis A, B, or C


  • Sepsis

  • Autoimmune diseases, including rheumatoid arthritis

  • Leukaemia

  • Myelodysplastic syndromes

  • Other considerations

    Neutrophils are important because, unlike some of the other white blood cells, they aren’t limited to a specific area of circulation. They can move freely through the walls of veins and into the tissues of your body to immediately attack all antigens.