Does this test have other names?
ANA, fluorescent antinuclear antibody test, FANA
What is this test?
This blood test is done to help your healthcare provider find out if you have an autoimmune
disease. Your immune system is your body's defense system. It protects you against
foreign invaders like viruses and bacteria. In some cases, your immune system can
become confused. It can think that normal cells in your body are foreign invaders.
When that happens, your body can make proteins called antibodies that attack your
When antibodies attack cells in your body, they cause swelling and redness known as
inflammation. Antinuclear antibodies attack normal proteins in the center structure
(nucleus) of your body's cells. Antinuclear antibodies are found in many autoimmune
diseases. These include lupus, scleroderma, and rheumatoid arthritis.
Why do I need this test?
Your healthcare provider may order this test if you have symptoms of an autoimmune
disease. Common symptoms of autoimmune diseases that may stem from antinuclear antibodies
What other tests might I have along with this test?
Finding antinuclear antibodies in your blood tells your healthcare provider only that
you may have an autoimmune disease. It doesn't tell him or her which disease you have. Your
provider may order other tests depending on your symptoms and your physical exam.
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses
to do the test. Even if your test results are different from the normal value, you
may not have a problem. To learn what the results mean for you, talk with your healthcare
A positive test for ANA does not mean you have an autoimmune disease. The test finds
small amounts of these antibodies in up to 15% of healthy people. Antinuclear antibodies
are measured in titers. A titer above 1:160 is a positive test result. A positive
result may mean:
You have systemic lupus erythematosis, or SLE. About 95% of people with this autoimmune
disease test positive for antinuclear antibodies.
You have another type of autoimmune disease.
You have a short-term condition, like an infection, that's causing your antinuclear
antibodies to go up.
You are one of the 15% of normal people who have positive antinuclear antibodies without
How is this test done?
The test requires a blood sample, which is drawn through a needle from a vein in your
Does this test pose any risks?
Taking a blood sample with a needle carries small risks that include bleeding, infection,
bruising, and a sense of lightheadedness. When the needle pricks your arm, you may
feel a slight sting or pain. Afterward, the site may be sore.
What might affect my test results?
Many conditions can trigger a positive antinuclear antibody test even without an autoimmune
disease. Conditions that may cause a "false positive" test include:
How do I get ready for this test?
You don't need any special preparation for this test. Tell your healthcare provider
whether you have had any recent or long-term infections. Also, let your provider know
about any medications you are taking, including over-the-counter medications, herbs,