Interpret Your Anti-TPO Antibodies Results
Enter your Anti-TPO value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
Anti-TPO Antibodies Normal Ranges
Anti-thyroid peroxidase (Anti-TPO) antibodies are autoantibodies that attack thyroid peroxidase, an enzyme essential for thyroid hormone synthesis.
| Reference Range | Unit | Notes |
|---|---|---|
| 0 – 34 | IU/mL | Negative <34 |
Also reported in: kIU/L.
Why Doctors Order the Anti-TPO Antibodies Test
Anti-TPO antibodies are positive in >90% of Hashimoto's thyroiditis and 70–80% of Graves' disease. Their presence predicts progression from subclinical hypothyroidism to overt hypothyroidism and from euthyroidism to hypothyroidism over time.
How to Enter Your Anti-TPO Result
Anti-TPO Antibodies can be reported in IU/mL or kIU/L. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
What a Low or High Anti-TPO Can Be Associated With
Below the reference range
- Not clinically applicable (negative is normal)
Above the reference range
- Hashimoto's thyroiditis (most common)
- Graves' disease
- Postpartum thyroiditis
- De Quervain's (subacute) thyroiditis
- Other autoimmune conditions: type 1 diabetes, rheumatoid arthritis, SLE
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your Anti-TPO Result
Before you read too much into a result, consider whether any of these applied:
- Low-level positivity is common in healthy women (especially elderly)
- Anti-TPO titers do not correlate with disease severity
Preparing for the test: No special preparation required.
Symptoms That Often Prompt Anti-TPO Testing
- Hypothyroidism symptoms (Hashimoto's): fatigue, weight gain, cold intolerance, hair loss
- Hyperthyroidism symptoms if in active phase
- Neck swelling or goiter
- Postpartum depression (if postpartum thyroiditis is the cause)
Want the full clinical guide to Anti-TPO Antibodies?
Reference ranges, causes, symptoms, preparation, and FAQs.