Blood test
Antinuclear Antibody Test
An antinuclear antibody (ANA) test looks for antibodies that attack the body’s own cells, used to help diagnose autoimmune conditions such as lupus.
Quick answer
Antinuclear Antibody Test: what it is and what the results mean
An ANA test is a blood test that detects antinuclear antibodies — proteins made by the immune system that mistakenly target the nucleus of the body’s own cells. It is a screening test for certain autoimmune diseases.
- Why it is done: It is used when an autoimmune connective tissue disease is suspected, such as lupus (SLE), Sjögren’s syndrome or scleroderma, in people with symptoms like joint pain, rashes, fatigue and unexplained inflammation.
- Understanding results: A positive ANA supports but does not confirm an autoimmune disease, as some healthy people test positive.
What it is
An ANA test is a blood test that detects antinuclear antibodies — proteins made by the immune system that mistakenly target the nucleus of the body’s own cells. It is a screening test for certain autoimmune diseases.
Why it is done
It is used when an autoimmune connective tissue disease is suspected, such as lupus (SLE), Sjögren’s syndrome or scleroderma, in people with symptoms like joint pain, rashes, fatigue and unexplained inflammation.
What to expect
It is an ordinary blood test taken from a vein in the arm, needing no special preparation. Results usually take several days and may include a titre (strength) and pattern.
Understanding the results
A positive ANA supports but does not confirm an autoimmune disease, as some healthy people test positive. A negative result makes lupus unlikely. Positive results are usually followed by more specific antibody tests.
Good to know
Risks and limitations
It is a very safe blood test. Because a positive result can occur without disease and rises with age, it must always be interpreted alongside symptoms and further tests, not on its own.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Antinuclear Antibody Test: frequently asked questions
Does a positive ANA mean I have lupus?
No. Many people with a positive ANA do not have lupus or any autoimmune disease. It is a starting point that is interpreted with your symptoms and confirmed with more specific tests.
Can a healthy person have a positive ANA?
Yes. A low-level positive ANA is fairly common, especially with increasing age, and does not necessarily indicate disease. Its significance depends on the strength of the result and your symptoms.
Related tests
Other blood test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
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