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Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

Hematology

Neutrophils: Insight Into Your Immune Defence

Neutrophils are the most common white blood cells and your first defence against bacterial infections. As part of your complete blood count, the neutrophil count gives insight into how your immune system responds. A high count often fits an infection or inflammation, while a low count can leave you more vulnerable.

What It Measures

Neutrophils are the most common white blood cells and form your first line of defence against bacterial infections. They circulate in your blood, ready to travel quickly to a site of infection or inflammation, where they clear away bacteria.

This test measures how many neutrophils are present in your blood. The count is determined within a complete blood count with differential, in which the five types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils and basophils) are counted separately.

The result can be shown as an absolute number or as a percentage of all white blood cells. Your doctor looks at both to assess whether your immune defence is in balance.

Why It Matters

Because neutrophils respond so quickly to invaders, their number says a lot about how your immune defence stands at that moment. A raised count (neutrophilia) often fits with a bacterial infection, inflammation, tissue damage or physical stress. The count can also rise temporarily after heavy exertion or with certain medications.

A reduced count (neutropenia) makes you more susceptible to infections. This can arise from certain viral infections, medications, a shortage of vitamin B12 or folate, or problems with production in the bone marrow.

Neutrophils are always assessed in relation to the other white blood cells. The ratio between neutrophils and lymphocytes can help your doctor judge whether an infection is more likely bacterial or viral.

When to Test

Neutrophils are measured when you have a complete blood count with differential. This is often done with fever, a (suspected) infection or with general complaints for which your doctor wants to find the cause.

The value is also important to monitor during treatments that can affect the production of white blood cells, or when an abnormal count was found previously.

Because the neutrophil count fluctuates with factors such as stress, exertion and time of day, your doctor always interprets a result in the context of your symptoms and, if needed, a repeat measurement.

Symptoms

Low Levels

A low neutrophil count often causes no symptoms on its own, but it does make you more susceptible to infections. Recurring or hard-to-heal infections, mouth ulcers, sore throat or fever can be clues. With a strongly reduced count it is wise to contact your doctor quickly if you develop a fever.

High Levels

A raised neutrophil count usually causes no symptoms by itself; the symptoms relate to the underlying cause. With a bacterial infection you might have fever, pain or local signs of inflammation. The count can also be temporarily raised after physical stress, surgery or intensive exertion without you feeling ill.

Lifestyle Tips

A healthy lifestyle with enough rest, good hand hygiene and a varied diet supports a resilient immune system.

Neutrophils respond sensitively to stress and recovery, so enough sleep and a good balance between exertion and rest help limit fluctuations. A one-off mild deviation is often harmless, but a persistently high or low count should be assessed by a doctor, especially when combined with symptoms.

Frequently Asked Questions

What does a high neutrophil count mean?
A high count (neutrophilia) often accompanies a bacterial infection, inflammation or physical stress. Your doctor interprets it alongside your symptoms and the rest of your blood count.
What does a low neutrophil count mean?
A low count (neutropenia) can make you more vulnerable to infections and may be caused by certain medications, viral infections or other conditions.
Are neutrophils part of a complete blood count?
Yes. Neutrophils are one of the five types of white blood cells reported in the differential of a complete blood count (CBC).
What is a normal neutrophil count?
In adults the absolute neutrophil count usually lies roughly between 2 and 7 x 10⁹/l, but the exact reference range differs per laboratory. Check the range shown on your own result.
What is the neutrophil-to-lymphocyte ratio?
This is the ratio between the number of neutrophils and lymphocytes. Your doctor may use it as an additional clue, for example to judge whether an infection is more likely bacterial or viral, or as a general measure of inflammation.
Can stress and exercise affect my neutrophils?
Yes. Physical stress, intensive exertion and even the time of day can temporarily raise the neutrophil count. That is why your doctor always interprets a result in the context of your situation and repeats it if needed.