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White Blood Cell Differential: About Your Child's Test

What is it?

A white blood cell differential counts the different types of white blood cells in a blood sample. There are five main kinds of white blood cells. The numbers of each type of white blood cell give information about your child's immune system.

Why is this test done?

The test helps your doctor decide if your child has an infection or serious illness. It can also help measure certain allergic reactions. It can help your doctor see how well any treatment for cancer is working.

How do you prepare for the test?

In general, you don't need to prepare before your child has this test. Your child's doctor may give you some specific instructions.

How is the test done?

A health professional takes a sample of your blood.

How long does the test take?

This test will take a few minutes.

Follow-up care is a key part of your child's treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if your child is having problems. Ask your doctor when you can expect to have your child's test results.

Where can you learn more?

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