ANA (Antinuclear Antibody) Test Test
An ANA test looks for antinuclear antibodies in your blood. A large number may be a sign of an autoimmune disorder, but the test alone cannot diagnose a specific disease.
What this test measures
An ANA test measures the level of antinuclear antibodies in your blood. These antibodies attack healthy cells instead of foreign substances.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
A positive result may be a sign of systemic lupus erythematosus (SLE), another autoimmune disease, a viral infection, or another health condition like cancer. Your provider will likely order more tests.
Lower-than-normal results
A negative result means antinuclear antibodies were not found, and you're less likely to have an autoimmune disorder. But it doesn't completely rule out the possibility.
Frequently asked questions
What is an ANA test?
An ANA test is a blood test that looks for antinuclear antibodies, which attack healthy cells instead of foreign substances.
Can a positive ANA test diagnose a disease?
No, an ANA test alone cannot diagnose a specific disease. Your provider will use other tests and your health information to make a diagnosis.
What does a negative ANA test mean?
A negative result means antinuclear antibodies were not found, and you're less likely to have an autoimmune disorder. But it doesn't completely rule it out.
Can healthy people have a positive ANA test?
Yes, some healthy people have antinuclear antibodies, and levels tend to increase with age. Many healthy adults, especially women over 65, may have a positive result.
What conditions are associated with a positive ANA test?
A positive result may be a sign of systemic lupus erythematosus (SLE), other autoimmune diseases, viral infections, or other health conditions like cancer.
Related lab tests
Sources
- MedlinePlus: ANA (Antinuclear Antibody) Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.