Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
TPO antibodies are common in Hashimoto's. TSI or TRAb point to Graves' disease.
Why it's done
- An abnormal TSH
- Goiter
- Pregnancy with thyroid concerns
Getting ready and what happens
- No special preparation is needed.
How the test is done
- A health worker cleans the skin, puts a band around your arm, and draws blood from a vein with a small needle. It takes a few minutes.
What the results mean
Positive TPO
Suggests Hashimoto's. You may develop an underactive thyroid over time, so TSH is checked regularly.
Positive TSI or TRAb
Supports Graves' disease.
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related tests
Sources
Last updated 2026-11-13.