ANA test

Overview

An ANA test is a blood test. Also called an antinuclear antibody test, it checks for antibodies in the blood that are not typical. Most often, the immune system makes antibodies to help fight infection. But antinuclear antibodies may attack the body's own tissues. This is called an autoimmune condition.

If you have a positive ANA test, it may mean that you have an autoimmune condition. But some people have positive ANA tests even when they don't have an autoimmune condition.

Why it's done

A healthcare professional orders an ANA test for a suspected autoimmune condition. These include lupus, rheumatoid arthritis, Sjogren syndrome and scleroderma.

An ANA test by itself can't confirm a diagnosis. But it can help rule out some conditions. And if the ANA test is positive, the results of more testing and your symptoms and exam findings may lead to a diagnosis.

Risks

The main risk linked with blood tests is soreness or bruising where the blood is taken from a vein in the arm. Most people don't have serious reactions to having blood drawn.

How you prepare

An ANA test uses a sample of your blood. If you're having just the ANA test, you can eat and drink as usual before the test. If you're also having other blood tests, you might need to not eat or drink for a time before the test. Your healthcare team tells you what to do.

Certain medicines may affect test results. So bring with you a list of the medicines you take.

What you can expect

For an ANA test, a member of your healthcare team takes a sample of blood by putting a small needle into a vein in your arm. The blood sample goes to a lab for study. You can return to your usual activities right after the test.

Results

The presence of antinuclear antibodies is a positive test result. But having a positive result doesn't mean you have an autoimmune condition. Many people who don't have an autoimmune condition have positive ANA tests. This is most likely to be true of people assigned female at birth who are older than 65.

Some infections, cancers and medicines have been linked with antinuclear antibodies. If you have a positive ANA test, your healthcare professional is likely to order more tests. The result of your ANA test is one piece of information that can help find the cause of your symptoms.