ANA (Antinuclear Antibody) Test
Reviewed
Also called: Antinuclear antibody panel, Fluorescent antinuclear antibody (FANA), ANA reflexive panel
An ANA test is a blood test that looks for antinuclear antibodies in your blood. It is used to help diagnose autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis, scleroderma, Sjögren's syndrome, Addison disease, autoimmune hepatitis, and thyroid diseases.
Specimen: Blood
Why this test may be ordered
- Fever
- Rash, blisters, or skin color changes
- Fatigue
- Joint pain, stiffness, and swelling
- Muscle pain
Preparation and collection
Some medicines may affect the results. You may need to stop taking certain medicines before this test, so tell your provider about everything you take. Do not stop taking any medicines unless your provider tells you to.
Blood sample from a vein in your arm.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Understanding results
Results from an ANA test alone cannot diagnose a specific disease. Your provider will use your ANA test results along with other blood and imaging tests and information about your health to make a diagnosis.
- Negative: Antinuclear antibodies were not found in your blood, and you are less likely to have an autoimmune disorder. Limitation: A negative result does not completely rule out the possibility that you could have an autoimmune disorder. Next step: Your provider will interpret this result in the context of your overall health.
- Positive: Antinuclear antibodies were found in your blood. This may be a sign of systemic lupus erythematosus (SLE), a different type of autoimmune disease, a viral infection (usually temporary), or another health condition such as cancer. Limitation: Having antinuclear antibodies in your blood does not always mean you have a disease. Some healthy people, especially women over 65, may have a positive result, and certain medicines can also cause antinuclear antibodies. Next step: Your provider will likely order more tests to make a diagnosis.
- You may feel a little sting when the needle goes in or out; slight pain or bruising at the puncture site is possible but most symptoms go away quickly.
- A negative result does not completely rule out an autoimmune disorder.
- A positive result does not always mean you have a disease; some healthy people, especially women over 65, may have a positive result, and certain medicines can also cause antinuclear antibodies.
What to do next
If your ANA test results are positive, your provider will likely order more tests to make a diagnosis.
- What do my ANA test results mean in my specific situation?
- Do I need any follow-up tests based on my results?
- Should I stop any of my current medicines before this test?
Evidence source
U.S. National Library of Medicine: ANA (Antinuclear Antibody) Test