ANA test results interpretation
| Result | Interpretation |
|---|---|
| Negative / <1:40 | Normal — autoimmune disease very unlikely |
| 1:40 to 1:80 | Low positive — weakly positive, found in 20–30% of healthy people |
| 1:160 to 1:320 | Moderate positive — more significant, further testing warranted |
| ≥1:640 | High positive — strongly suggests autoimmune disease |
What does a positive ANA mean?
Positive ANA is common — but not always disease
ANA is positive in about 95% of people with lupus (SLE), but also in 5–15% of completely healthy people — especially women and older adults. A positive ANA alone does not diagnose any disease. The titre (level) and pattern (speckled, homogeneous, nucleolar) help direct further testing. Further specific antibodies are tested when ANA is significantly positive: anti-dsDNA and anti-Sm for lupus; anti-Ro/La for Sjögren's; anti-Scl-70 for scleroderma; anti-Jo-1 for myositis.
Conditions associated with positive ANA
| Condition | ANA positivity rate |
|---|---|
| Systemic Lupus Erythematosus (SLE) | ~95% |
| Sjögren's syndrome | ~80% |
| Scleroderma | ~80% |
| Rheumatoid arthritis | ~30–40% |
| Healthy individuals | 5–15% |
Questions to ask your doctor
- What is my ANA titre and pattern?
- Do I need further antibody tests (anti-dsDNA, anti-Ro)?
- Should I see a rheumatologist?
- Could my symptoms be explained by lupus or Sjögren's?
Medical Disclaimer: For educational purposes only. Always consult a qualified healthcare professional for diagnosis and treatment.