ANA (Antinuclear Antibody) Test
Reviewed
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.
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.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- 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.
Evidence source
U.S. National Library of Medicine: ANA (Antinuclear Antibody) Test