Antinuclear antibodies (ANA)

In brief

A blood test for antinuclear antibodies, used to screen for autoimmune rheumatic conditions such as lupus.

What it measures

Antinuclear antibodies (ANA), autoantibodies that attack the nucleus of healthy cells, reported as a titre and a pattern.

Why it is done

To screen for conditions such as systemic lupus erythematosus (SLE), scleroderma and Sjögren's disease.

Reading the results

• A titre of 1:160 or higher is often considered positive.
• Many healthy people have low levels of ANA, and a positive result can also occur with infections, thyroid disorders, some medicines and cancers.
• A positive result may lead to more specific antibody tests.

Before the test

None.

What can affect the result

• Infections
• Thyroid disorders
• Some medicines
• Cancers

Related topics

• AutoimmunityBody state
• Immune toleranceProcess

Sources

1. Antinuclear antibodiesPathology Tests Explained, last reviewed 7 March 2026

Test information summarised from the sources listed on this page, read on 19 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.