White Blood Cell Count | Lab Tests Online-UK

Also Known As

WBC

Leucocyte count

White count

Formal Name

White Blood Cell Count

This article was last reviewed on

30 September 2024.

This article waslast modified on 9 January 2025.

At a Glance

Why Get Tested?

If your doctor thinks that you might have an infection, inflammatory illness, immune deficiency, bone marrow disease or allergy and; to monitor treatment

When To Get Tested?

As part of a full blood count (FBC), which may be requested for a variety of reasons

Sample Required?

A blood sample taken from a vein in your arm or from a finger-prick or in babies a heel-prick

Test Preparation Needed?

None

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

What is being tested?

The white blood cell (WBC) count indicates the number of white blood cells in a sample of blood. This count provides a clue to the presence of illness. White blood cells are made in the bone marrow and protect the body against infection and aid in the immune response. If an infection develops, white blood cells attack and destroy the micro-organism causing the infection.

How is the sample collected for testing?

The blood sample is obtained by a needle placed in a vein in the arm or from a finger-prick or heel-prick (for newborns).

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

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