Thyroid antibodies
Also known as:
TPO antibodies, thyroglobulin antibodies, TSH receptor antibodies (TRAb, TSI)
Antibodies explain why the thyroid is failing or overactive, and help guide pregnancy care.
Written and reviewed by Farhan Tahir, MD · Last reviewed
VIDEO LESSON
What they measure
These tests detect immune proteins aimed at the thyroid. TPO and thyroglobulin antibodies mark Hashimoto's; TSH receptor antibodies (TRAb or TSI) drive Graves' disease.
When they help
• A raised TSH: positive TPO antibodies suggest Hashimoto's and a higher chance of progression
• Confirming Graves' disease without a scan
• Pregnancy with current or past Graves' disease: TRAb can cross the placenta
• Predicting remission before stopping antithyroid drugs
Good to know
Many people have positive TPO antibodies with normal thyroid function and need monitoring only. The 2026 ATA pregnancy guideline advises against levothyroxine for euthyroid TPO-positive women.
Key studies and references
Educational content only, written and reviewed by Farhan Tahir, MD. It does not replace individual medical advice. For sudden chest pain, trouble breathing or stroke symptoms, call 911.
AT A GLANCE
Test type
Thyroid
Also known as
TPO antibodies, thyroglobulin antibodies, TSH receptor antibodies (TRAb, TSI)
Reviewed by
Farhan Tahir, MD
Questions about your own care?
Dr. Tahir’s team offers consults through Youthful Medicine.
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