Your Report Says “TPO Antibodies: High.” Nobody Explained It.
You opened the patient portal expecting nothing new, and there it was: a flagged result, a line of red text, and the words “TPO antibodies: high.” Underneath, maybe a note from the office saying “we’ll keep an eye on it,” and not much else. No explanation of what a thyroid peroxidase antibody even is, no context for whether high TPO antibodies mean something is actually wrong, and no next step beyond a follow-up appointment a year from now.
You did the responsible thing. You asked for bloodwork when something felt off, and what came back was a number instead of an answer. That gap, between having a result and understanding it, is its own particular kind of exhausting, and it deserves more than a shrug.
What TPO Antibodies Actually Are
Thyroid peroxidase, or TPO, is an enzyme inside your thyroid gland. Its job happens almost entirely behind the scenes: it helps convert iodine into a form your thyroid can use to build thyroid hormone. Without it, hormone production stalls.
TPO antibodies are proteins your immune system makes when it mistakes that enzyme for something dangerous. The National Institute of Diabetes and Digestive and Kidney Diseases describes thyroid peroxidase antibodies as “a type of thyroid antibody that is present in most people with Hashimoto’s disease.” In plain terms, it is your immune system’s own security system, tuned to a part of you it was supposed to protect.
Think of a home security system that has started flagging the homeowner. The alarm isn’t the problem; it’s a signal that the targeting has gone wrong somewhere upstream. A positive TPO antibody result works the same way.
It doesn’t tell you how much damage has been done, or whether your thyroid is currently struggling to keep up. It tells you the immune system has your thyroid tissue in its sights.
Hashimoto’s vs Hypothyroidism: The Process and the Outcome
Hashimoto’s and hypothyroidism get used almost interchangeably, and that’s part of why a flagged antibody result is so confusing. They aren’t the same thing. Hashimoto’s thyroiditis is the process: the immune system gradually attacking thyroid tissue over months or years. Hypothyroidism is the outcome, what happens once enough of that tissue has been affected that your thyroid can no longer keep up with demand.
You can be well into the process without having reached the outcome yet. A woman in Brentwood with high TPO antibodies and a normal TSH may be years into an autoimmune process her labs haven’t fully caught up to, which is a very different situation than “nothing is happening,” even though both can look identical on a single lab report.
The 2012 American Thyroid Association and American Association of Clinical Endocrinologists guideline on hypothyroidism is direct about this: in the United States and other iodine-sufficient countries, it’s an autoimmune process, not the gland simply wearing out, that accounts for most cases of an underactive thyroid. That same guideline notes that the large majority of people with Hashimoto’s show elevated antibody titers on testing. That’s the root cause question worth asking before a TSH number ever crosses into “abnormal”: not just what your thyroid is doing right now, but why.
Hashimoto’s also belongs to a much larger family of autoimmune conditions, and if autoimmunity beyond the thyroid is part of your story, our broader guide to functional medicine for autoimmune disease walks through how we think about that bigger picture.
High TPO Antibodies With a Normal TSH
This is the exact situation so many women land in: high TPO antibodies with a normal TSH. The screening number looks fine. The antibody flag does not. And the two results seem to be telling you different things.
Here’s what the evidence actually shows. A landmark 20-year study out of Whickham, England, followed thousands of adults and found that having positive thyroid antibodies significantly raised the risk of developing hypothyroidism over time, even when the starting TSH was normal. The 2012 ATA/AACE guideline cites that same research with a specific number: people with positive TPO antibodies progress to overt hypothyroidism at roughly 4.3% per year, compared with about 2.6% per year for people with the same borderline thyroid findings and negative antibodies.
That’s not a guarantee anything will happen. It’s a meaningfully higher chance that, over years, something will.
In my practice, the woman I see most often was told to come back in a year, and spends that year feeling steadily worse without anyone building a plan around what her labs were already showing. “We’ll watch it” is a medically defensible response to a normal TSH. It is also, understandably, not a satisfying one when you’re the person doing the waiting.
There’s research that helps explain why the waiting feels bad. A 2024 study in Scientific Reports compared people with positive thyroid antibodies whose thyroid function was still technically normal to healthy people with no antibodies at all. The antibody-positive group reported significantly more fatigue, digestive symptoms, and brain fog, and their antibody levels tracked with markers of inflammation.
It’s a small study, and it shows a correlation, not proof that the antibodies themselves cause those symptoms. But it’s real evidence that a normal TSH and feeling fine are not the same thing, and that your experience deserves more curiosity than a single number can offer.
Why a TSH-Only Test Can Miss the Story
TSH is the standard first screen, and for good reason: it’s inexpensive, reliable, and reflects how hard your pituitary gland is working to get your thyroid to produce hormone. But TSH is one measurement inside a feedback loop, and a feedback loop can look steady even while something inside it is quietly changing.
TSH doesn’t tell you why. It doesn’t tell you whether an autoimmune process is underway, or how much usable hormone your body has on hand day to day. That’s the piece a fuller thyroid panel adds, and it isn’t something to re-walk here.
Our main thyroid page covers exactly what a complete panel includes and why. The full picture, from TSH through antibodies, lives there. Labs are one piece of that picture; a TPO result is what tells you which piece is missing.
What We Look at Alongside the Thyroid in Franklin
At The Healing Place in Franklin, TN, as part of a fuller thyroid workup, we look at both antibody types, TPO and thyroglobulin, alongside our Custom Comprehensive Metabolic Panel. But an antibody result is also a starting point for a few other questions, not a lab value to chase on its own.
Selenium is one of the most talked-about pieces of this conversation, and it deserves an honest answer. A Cochrane review of selenium supplementation for Hashimoto’s thyroiditis found that selenium can lower TPO antibody levels on a lab report. What it didn’t find is clear evidence that the change translates into feeling better, and the reviewers were careful to say the evidence remains incomplete. A number moving on a page and a body feeling different are not automatically the same thing.
Vitamin D status is worth the same honesty. Researchers pooling case-control data on autoimmune thyroid disease, published in Nutrients, found lower vitamin D levels among affected patients than among people without thyroid disease, with the gap widening further inside the Hashimoto’s group specifically. That’s an association, not proof that low vitamin D causes the antibody response, since the study’s own authors say more research is needed to sort out which direction the relationship runs. It’s a reasonable thing to check, not a fix.
The gut is part of this picture too. A meta-analysis in the journal Thyroid found that roughly 1 in 60 people with autoimmune thyroid disease also has biopsy-confirmed celiac disease, which is why an unexplained TPO result is often a reasonable moment to ask about gut health, not just thyroid health.
And then there’s the piece that doesn’t show up on any panel at all: how your nervous system is holding up under everything else going on. Chronic stress keeps the body geared toward defense, and that can add extra strain to an immune system that’s already working overtime.
This is where Dr. Anthony’s INSIGHT scan comes in: a short, in-office scan that puts an actual number on your nervous system’s stress load instead of leaving it to a guess. Pairing that number with your thyroid and antibody results is what a whole-body approach looks like in practice, whether you’re coming from downtown Franklin or driving in from Cool Springs.
TPO Antibodies and Pregnancy
If you’re pregnant, or hoping to be, a positive TPO result raises different questions, and this is a place for careful, hedged language rather than alarm.
The American Thyroid Association’s 2017 guideline on thyroid disease in pregnancy reports that up to 18% of pregnant women test positive for thyroid antibodies, and that antibody-positive women show a higher rate of pregnancy loss and preterm delivery in pooled research. The same guideline is direct about what that does and doesn’t mean: a clear association has been demonstrated between thyroid antibodies and pregnancy loss, but it “does not prove causality,” and the mechanisms behind it remain unclear.
The guideline also states there isn’t enough evidence to recommend for or against treatment aimed specifically at preventing pregnancy loss in an otherwise healthy, antibody-positive pregnant woman, and it recommends against selenium for this group specifically. What this means for you is simple: a positive TPO result during pregnancy is worth a direct conversation with your OB or your endocrinologist, someone who can weigh your full history and monitor your thyroid through the pregnancy. That conversation, not a general health article, is where a plan for your pregnancy gets made.
Working With Your Endocrinologist, Not Around Them
None of this replaces your endocrinologist or your primary care provider, and it isn’t meant to. If your thyroid function has already declined enough to need it, levothyroxine or another thyroid hormone medication is standard, appropriate medical care, not something to skip or second-guess. We would never suggest changing, delaying, or stopping a prescribed medication based on anything in this article.
What functional medicine adds is a longer look at the factors sitting upstream of your thyroid: gut health, nutrient status, and the stress load your nervous system is carrying. Your endocrinologist manages the diagnosis and the medication. Our role, when it fits, is to join your care team and look at the broader terrain your thyroid is operating in, never as a substitute for that care, always as a second set of eyes on the whole picture.
Frequently Asked Questions
Should I be worried about high TPO antibodies?
Worry isn’t the useful response here, but attention is. A high TPO antibody result means your immune system may be involved in your thyroid story, and it’s worth understanding, tracking over time, and discussing with your provider. On its own, it is not a diagnosis of disease or a sign that something urgent is happening.
How do you treat high TPO antibodies?
You don’t treat the antibody number itself. Care focuses on your thyroid function, your symptoms, and the factors that may be contributing to the immune response, with thyroid hormone medication as the standard treatment once hypothyroidism develops. A functional medicine workup can look at the surrounding picture, but it works alongside your prescribing provider, not around them.
What level of TPO antibodies means Hashimoto’s?
There isn’t one number that applies to everyone. Lab reference ranges vary between labs, and a diagnosis depends on the full picture: your antibody levels, your thyroid function tests, and your symptoms, read together by your provider rather than off a single cutoff on a report.
Can TPO antibodies go down?
Research on selenium supplementation has shown it can lower TPO antibody levels on lab testing, but a Cochrane review found the evidence doesn’t yet show that a lower number translates into feeling better. Antibody levels are worth tracking, but they aren’t a target to chase on their own.
What is the sister disease to Hashimoto’s?
Graves’ disease is often mentioned alongside Hashimoto’s because both are autoimmune thyroid conditions. Where Hashimoto’s typically slows the thyroid down, Graves’ disease pushes it into overdrive, causing hyperthyroidism rather than hypothyroidism.
Getting a Clearer Thyroid Picture in Franklin
A flagged antibody result and a note that says “we’ll keep an eye on it” is not the same as an answer, and you are allowed to want more than that. It’s a familiar reason people first call our office on Columbia Avenue in Franklin.
Dr. Amy and our functional medicine team will sit down with your labs and work out, together, what they actually mean for your thyroid and your care. Schedule a consultation, and let’s start there.
This page is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or a qualified health provider about your health and before beginning any new care.
