ANA (Antinuclear Antibody) Test

An ANA test is a blood test that looks for antinuclear antibodies in your blood. Antibodies are proteins that your immune system makes to fight foreign substances, like viruses and bacteria. But an antinuclear antibody attacks your healthy cells instead.

It's called 'antinuclear' because it targets the nucleus of the cells, which is in charge of sending signals that are needed for important cell functions. It's normal to have a few antinuclear antibodies in your blood. But a large number may be a sign of an autoimmune disorder.

If you have an autoimmune disorder, your immune system attacks the healthy cells of your organs and tissues by mistake. These disorders can cause serious health problems.

Why this test is done

Your health care provider may order an ANA test if you have symptoms of an autoimmune disorder. The symptoms depend on what part of your body is affected. They may include:

• Fever
• Rash, blisters, or skin color changes
• Fatigue
• Joint pain, stiffness, and swelling
• Muscle pain
• Swollen glands
• Abdominal (belly) pain

How to prepare

Some medicines may affect the results of your ANA test. You may need to stop taking certain medicines before this test, so tell your provider about everything you take. But don't stop taking any medicines unless your provider tells you to.

Sample type

Blood

Other names for this test

antinuclear antibody panel, fluorescent antinuclear antibody, FANA, ANA, ANA reflexive panel