Anti-TPO antibodies attack thyroid peroxidase, an enzyme the thyroid needs to make hormones. Their presence means the immune system is targeting the thyroid.
- Normal range (adults)
- Up to 34 IU/mL
- Sample
- Blood
- Fasting
- Not usually needed
- Also called
- Thyroid Peroxidase Antibodies, TPOAb, Anti-TPO, TPO Ab, Thyroid Peroxidase Ab
Anti-TPO Antibodies normal range
| Group | IU/mLSame unit in all countries |
|---|---|
| Adults | Up to 34 |
Ranges vary slightly between laboratories. The range printed on your own report is the one to go by.
Why is the Anti-TPO Antibodies test done?
They are used to find the cause of thyroid problems, especially Hashimoto's thyroiditis, and to assess risk in pregnancy.
What does a high Anti-TPO Antibodies level mean?
Positive TPO antibodies mean autoimmune thyroid disease, most often Hashimoto's. Your thyroid may work normally for years, but your risk of developing hypothyroidism is higher.
Common causes
- Hashimoto's thyroiditis
- Graves' disease
- Other autoimmune conditions
- A family history of thyroid disease
- Sometimes found in healthy people, especially women
Diet and lifestyle tips
- Use iodised salt normally but avoid high-dose iodine and seaweed supplements
- Make sure your selenium and vitamin D are adequate through diet
- Eat a balanced, minimally processed diet
- Get TSH checked regularly as your doctor advises
When should you see a doctor?
If you are positive, have your TSH checked every year, and before and during pregnancy.
Last updated
This page is for general education and is not a diagnosis. Normal ranges differ between laboratories, so always compare your result with the reference range printed on your own report, and discuss abnormal results with your doctor.