Thyroid antibodies (anti-TPO)
anti-TPO · TPO antibodies · thyroid peroxidase antibodies · Hashimoto's test
This is a blood test from a vein. It looks for antibodies that can attack your thyroid gland.
For changes in thyroid hormones, an enlarged thyroid, when planning a pregnancy, or for infertility.
⏱ Duration: the blood draw takes a few minutes; results usually come in 1 to 3 days
Be sure to tell your doctor
How to prepare
- Food. Strict fasting is usually not needed. But it is best in the morning before eating, or 3 to 4 hours after a light meal. Check with the lab.
- The day before. For 24 hours, no alcohol and no hard workouts. Best not to smoke in the morning.
- Medicines. Do not stop them on your own. Tell your doctor what you take. They will decide if anything should change.
What to bring
- Your test request form
- Your ID
- Past thyroid hormone tests and thyroid ultrasound, if you have them
How it goes
- You sit down and rest your arm on the armrest
- A band is tightened above your elbow
- The skin is wiped with antiseptic
- A quick prick, and blood fills a tube
- The needle comes out, and a cotton pad is pressed on the spot
What you'll feel
- A quick prick, like a pinch
- Sometimes slight dizziness. Tell the nurse
Afterwards
- Press the cotton pad for 3 to 5 minutes and keep your arm straight
- You can eat right away and go back to your usual day
- Results usually come in 1 to 3 days. The lab will tell you when
Common questions
Do high antibodies mean I am ill?
Not always. Many people have high antibodies and normal hormones. Your doctor looks at all the tests together.
Do I need to repeat anti-TPO often?
Usually not. Your doctor will tell you how often.