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Rheumatoid Factor: About Your Child's Test

What is it?

This test measures the amount of rheumatoid factor (RF) in your child's blood. RF is an antibody that can cause damage to normal body tissues.

High levels of RF in the blood can be caused by diseases such as rheumatoid arthritis (called juvenile idiopathic arthritis in children) or infections. But healthy people can also have high RF levels, so you may need other tests to find out why these levels are high.

Why is this test done?

The test is done to help confirm that your child has arthritis or some other inflammatory condition.

How do you prepare for the test?

You don't need to do anything before your child has this test.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm.

How long does the test take?

The test will take a few minutes.

What happens after the test?

  • Your child will likely be able to go home right away.
  • Your child can go back to his or her usual activities right away.

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 advice line (811 in most provinces and territories) 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?

Go to https://www.healthwise.net/patientEd

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