Test Overview

An antinuclear antibody (ANA) test measures the amount and pattern of antibodies in your blood that work against your own body (autoimmune reaction).

The body's immune system normally attacks and destroys foreign substances such as bacteria and viruses. But in disorders known as autoimmune diseases, the immune system attacks and destroys the body's normal tissues. When a person has an autoimmune disease, the immune system produces antibodies that attach to the body's own cells as though they were foreign substances, often causing them to be damaged or destroyed. Rheumatoid arthritis and systemic lupus erythematosus are examples of autoimmune diseases.

An ANA test is used along with your symptoms, physical examination, and other tests to find an autoimmune disease.

Why It Is Done

An ANA test is done to help identify problems with the immune system, such as:

• Rheumatoid arthritis.
• Lupus.
• Polymyositis.
• Scleroderma.
• Sjögren's syndrome.

How To Prepare

In general, there's nothing you have to do before this test, unless your doctor tells you to.

How It Is Done

A health professional uses a needle to take a blood sample, usually from the arm.

How long the test takes

The test will take several minutes.

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