What is the antinuclear antibodies test?

The antinuclear antibodies (ANA) test is a blood test of the immune system.

Another name for this test is FANA (fluorescent antinuclear antibodies) screen.

Why is this test done?

This test checks for antibodies that may be attacking your body’s own cells. Antibodies are the proteins your immune system makes to fight infections, such as the flu and measles. The immune system is your body’s defense against infection. If you have an autoimmune disease, your body also makes antibodies that attack normal, healthy tissue–for example, skin, blood vessels, or joints. This test can help make a diagnosis when you have symptoms of an autoimmune disease, such as lupus. This test may also be done to see how well treatment for a disease is working.

How do I prepare for this test?

• You may need to avoid taking certain medicines before the test because they might affect the test result. Make sure your healthcare provider knows about any medicines, herbs, or supplements that you are taking. Ask your provider before stopping any of your regular medicines.
• Talk to your healthcare provider if you have any questions about the test.

How is the test done?

Having this test will take just a few minutes. A small amount of blood is taken from a vein in your arm with a needle. The blood is collected in tubes and sent to a lab.

Ask your healthcare provider when and how you will get the result of your test.

What does the test result mean?

To make a diagnosis, your healthcare provider usually needs to consider the ANA test results along with your medical history, exam, other lab tests, and your symptoms over time. If your test result is positive, you may have an autoimmune disease. However, many people who do not have an autoimmune disease have a positive test result. It’s also possible to have a negative result even when you do have an autoimmune disease.

What if my test result is not normal?

Test results are only one part of a larger picture that takes into account your medical history, physical exam, and current health. Sometimes a test needs to be repeated to check the first result. Talk to your healthcare provider about the results and ask questions, such as:

• If you need more tests
• What kind of treatment you might need
• What lifestyle, diet, or other changes you might need to make