What is an ANA (antinuclear antibody) test?
An ANA test looks for antinuclear antibodies in your blood. If the test finds antinuclear antibodies in your blood, it may mean you have an autoimmune disorder. An autoimmune disorder causes your immune system to attack your own cells, tissues, and/or organs by mistake. These disorders can cause serious health problems.
Antibodies are proteins that your immune system makes to fight foreign substances like viruses and bacteria. But an antinuclear antibody attacks your own healthy cells instead. It’s called “antinuclear” because it targets the nucleus (center) of the cells.
Other names: antinuclear antibody panel, fluorescent antinuclear antibody, FANA, ANA
What is it used for?
An ANA test is used to help diagnose autoimmune disorders, including:
- Systemic lupus erythematosus (SLE). This is the most common type of lupus, a chronic disease affecting multiple parts of the body, including the joints, blood vessels, kidneys, and brain.
- Rheumatoid arthritis, a condition that causes pain and swelling of the joints, mostly in the hands and feet
- Scleroderma, a rare disease affecting the skin, joints, and blood vessels
- Sjogren’s syndrome, a rare disease affecting the body’s moisture-making glands
Why do I need an ANA test?
Your health care provider may order an ANA test if you have symptoms of lupus or another autoimmune disorder. These symptoms include:
- Red, butterfly-shaped rash (a symptom of lupus)
- Joint pain and swelling
- Muscle pain
What happens during an ANA test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for an ANA test.
Are there any risks to the test?
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.
What do the results mean?
A positive result on an ANA test means that antinuclear antibodies were found in your blood. You may get a positive result if:
- You have SLE (lupus).
- You have a different type of autoimmune disease.
- You have a viral infection.
A positive result doesn’t necessarily mean you have a disease. Some healthy people have antinuclear antibodies in their blood. In addition, certain medicines can affect your results.
If your ANA test results are positive, your health care provider will likely order more tests, especially if you have symptoms of disease. If you have questions about your results, talk to your health care provider.
Is there anything else I need to know about an ANA test?
Antinuclear antibody levels tend to increase with age. As many as one-third of healthy adults over the age of 65 may have a positive ANA test result.