Thyroid
Thyroglobulin Antibodies (TgAb)
Thyroid
Autoantibodies against thyroglobulin. Marker for autoimmune thyroid disease.
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Thyroglobulin is a protein produced by the thyroid gland that serves as the precursor and storage form of the thyroid hormones T4 and T3. When the immune system produces antibodies against thyroglobulin, it can signal autoimmune thyroid disease. Elevated thyroglobulin antibodies are commonly found in Hashimoto's thyroiditis and Graves' disease, and they are tested alongside TPO antibodies for a comprehensive autoimmune thyroid assessment.
Thyroglobulin antibody testing helps determine whether a thyroid disorder has an autoimmune basis. It is recommended if you have a known thyroid condition and want to explore an autoimmune component, if you have thyroid symptoms despite normal function tests, during pregnancy (approximately 20% of pregnant women carry elevated antibodies without awareness), or if you have a personal or family history of thyroid or autoimmune disorders.
What a high value can mean
A positive result indicates that the immune system is producing antibodies against thyroglobulin, suggesting autoimmune thyroid disease. When elevated alongside TPO antibodies, the most likely diagnosis is Hashimoto's thyroiditis, which typically presents with hypothyroid symptoms: high TSH, and low-to-normal T3 and T4. Thyroglobulin antibodies can also appear in Graves' disease.
What a low value can mean
A negative result means thyroglobulin antibodies were not detected at clinically significant levels. This reduces the likelihood of autoimmune thyroid disease but does not entirely rule it out. Some patients with confirmed autoimmune thyroiditis do not produce these antibodies. Repeat testing may be considered if symptoms persist.
No advance preparation is required. Bring valid identification to the appointment. If you take a supplement containing biotin (often sold for hair and nails), pause it for two days before the test, as high doses can distort the result.
Order your test
Choose your test and pay online. Your lab referral is created straight away.
Give your sample
Visit any of our partner sampling locations. No appointment needed at most of them.
The lab analyses it
Your sample is analysed at an accredited Swedish laboratory.
Get your results
Your values appear in your account with reference ranges and an explanation of each marker.
Yes. Testing both provides the most thorough autoimmune thyroid screening. Some patients may be positive for one but not the other, so combining the two tests increases diagnostic accuracy.
No. Thyroglobulin is a protein produced by the thyroid, while thyroglobulin antibodies are immune proteins that attack it. They are measured for different clinical purposes: thyroglobulin levels are often used in thyroid cancer monitoring, while antibodies indicate autoimmune activity.
Yes. Antibody levels can rise or fall depending on disease activity, treatment, and lifestyle factors. For consistent monitoring, use the same laboratory and methodology each time.