Yes, you can have Hashimoto’s, a normal TSH and still be exhausted. A normal TSH and T4 mean the thyroid hormone in your blood is within the usual range. They don’t measure what happens to that hormone inside your cells, and they don’t measure the immune activity that newer research links to Hashimoto’s fatigue. Common, treatable causes like low iron, low B12 and celiac disease also sit outside a basic thyroid panel.
Here’s what the research shows, including the parts that are still uncertain, and what you can take to your next appointment. Please don’t change your levothyroxine dose or start or stop a supplement because of anything here without talking to your doctor first.
Prefer to watch? This article goes with our video, Hashimoto's: Normal Labs, Still Exhausted (11 min).
Can you have Hashimoto’s with a normal TSH?
Yes, and it’s common. Hashimoto’s is an autoimmune disease: immune cells move into the thyroid and slowly damage it. Most people with it make antibodies against thyroid peroxidase (TPO), an enzyme the gland needs to build its hormones. Those antibodies can appear years before the thyroid stops keeping up, and many people who have them never reach that point.
In a large US survey of more than 17,000 people, about 11% tested positive for TPO antibodies, and positive results were more common in women and rose with age.1 Most of them had never been told they had a thyroid problem. A positive antibody test on its own isn’t a diagnosis, and many people who test positive never need treatment. So when people say “Hashimoto’s with normal labs,” they usually mean one of two groups: people diagnosed with Hashimoto’s whose thyroid is still keeping up without medication, and people on levothyroxine whose numbers are now back in range.
Both groups can feel worn out. A 2025 review in Frontiers in Endocrinology estimated that about 5 to 10% of people with Hashimoto’s keep having symptoms like fatigue, weight gain, feeling cold and low mood after their thyroid levels are normal.2 That sounds like a small slice until you remember how common the disease is. Hypothyroidism affects about 5 in 100 Americans, and Hashimoto’s is its leading cause.3
What a normal TSH actually tells you
TSH is a request, not a delivery. The pituitary, a small gland at the base of the brain, sends out TSH (thyroid-stimulating hormone) to tell the thyroid to work. The thyroid answers mostly with T4, a less active form of the hormone. When enough T4 is circulating, the pituitary eases off. That feedback loop is why TSH is usually the first number checked.
T4 isn’t the form that does most of the work, though. Inside cells in the brain, muscle and elsewhere, enzymes called deiodinases remove one iodine atom and turn T4 into T3, the active hormone that sets how fast a cell uses energy. A blood test sees the supply. It can’t see that last step inside the tissue.
Three explanations researchers are looking at
1. “Normal” is a population range
Every person’s TSH set point is a little different. A result inside the reference range is normal for a population, which isn’t quite the same as normal for you. Researchers also wondered whether a common variant in the gene for type 2 deiodinase, the enzyme that makes T3 inside tissues, might leave some people short of active hormone where it counts.
It was a reasonable idea, but it didn’t hold up in the largest test so far. In the UK Biobank, researchers compared 18,761 people taking levothyroxine with more than 360,000 people who weren’t. The treated group did report more tiredness than the controls. But carrying the gene variant made no difference to tiredness, well-being or reaction time.4 And a review of 18 studies found that adding T3 to standard T4 treatment didn’t beat T4 alone on fatigue, depression or quality of life.5 One detail from that review stuck with us: when patients were asked, 43% preferred the combination anyway, compared with 23% who preferred T4 alone. That gap suggests the standard approach doesn’t fully work for some people.
2. The immune attack doesn’t stop when the numbers do
Levothyroxine replaces missing hormone. It doesn’t switch off the autoimmune process that caused the shortage. An active immune response releases cytokines, the chemical messengers immune cells use to coordinate inflammation, and those messengers circulate well beyond the neck.
Cytokines alone can make a person exhausted. When patients were treated with interferon-alpha, an immune signaling protein once used as a medicine for hepatitis C and some cancers, most developed fatigue within weeks, and some went on to develop low mood and slowed thinking.6 Researchers call this pattern sickness behavior.7 It’s the reason a bad flu makes you want to lie completely still. Your brain reads certain immune signals as an order to save energy.
One of the most studied of those signals is interleukin-1. The body also makes a brake for it, the interleukin-1 receptor antagonist (IL-1Ra), and it makes more of that brake when interleukin-1 activity is high. That’s why researchers use IL-1Ra levels as a rough stand-in for how busy the pathway is.
3. What a 2026 study found in 36 people with normal labs
In July 2026, a Norwegian team published a study of 36 people with Hashimoto’s whose thyroid levels were all in the normal range.8 These were not people with mild complaints. Half of them rated their fatigue 85 or higher on a scale where 100 means as bad as it gets.
The researchers measured five things in their blood: TPO antibodies, IL-1Ra, two inflammatory cytokines (IL-6 and TNF-alpha), and heat shock protein 90-alpha, a protein that helps cells cope with stress. Then they compared each one against three questionnaires on fatigue and general health.
- IL-1Ra was the most consistent result. Higher levels went with poorer general health, and with more fatigue once the other markers were taken into account.
- Heat shock protein 90-alpha went the other way. People with more of it reported less fatigue.
- TPO antibodies showed no link to fatigue or general health in any analysis, even though they’re the test used to diagnose the disease.
That last point surprises a lot of people, because antibody levels are often treated as a measure of how “bad” Hashimoto’s is. Some earlier studies did find a link between antibodies and symptoms, so the question isn’t closed. The authors also point out that everyone in the study had high antibody levels, which makes a link harder to spot. Still, the result suggests the antibody number and the fatigue may be tracking different things.
What happened when surgeons removed the thyroid
The same Norwegian research network ran a very different experiment seven years earlier. In a randomized trial published in 2019 in the Annals of Internal Medicine, 150 people with Hashimoto’s were assigned either to keep their usual medical treatment or to have the whole thyroid removed.9 Everyone had normal hormone levels on medication, persistent symptoms and very high TPO antibodies (above 1,000 IU/mL).
After 18 months, only the surgery group had improved. Their general health score rose from 38 to 64 out of 100. The share with chronic fatigue fell from 82% to 35%. Their antibodies dropped sharply too, from a median of 2,232 to 152 IU/mL.
That’s a striking result, and it’s easy to over-read. Patients knew which treatment they got, and surgery can carry a strong expectation effect. Removing the thyroid has real risks: in this trial, about 5% of the surgery group had temporary damage to the nerve that moves a vocal cord, and about 4% had lasting low calcium. The authors say their results apply only to a subgroup of patients, and the 2025 review is clear that surgery is not a first-line option.2 What the trial does suggest is that the inflamed gland itself may be part of the problem, not only the hormone it fails to make.
The ordinary causes worth ruling out first
Immune-driven fatigue is the new and interesting part of this story. It’s also the part nobody can treat yet. Before landing there, it’s worth asking whether something common and checkable has been missed. Several of these are common in people with Hashimoto’s, and some are more common than in the general population.
| Possible cause | Why it matters in Hashimoto’s | What to ask about |
|---|---|---|
| Low iron stores | Iron and ferritin deficiency are common in women with Hashimoto’s, and the thyroid’s TPO enzyme needs iron to work.10 You can be low in iron before you’re anemic. | Ferritin, not only hemoglobin |
| Low vitamin B12 | A pooled analysis found B12 deficiency in about 18% of people with autoimmune thyroid disease.11 Some have autoimmune gastritis, which blocks B12 absorption. | B12, and whether antibody tests for the stomach make sense |
| Celiac disease | Biopsy-confirmed celiac disease turns up in about 1 in 62 people with autoimmune thyroid disease.12 | A celiac blood test, done while you’re still eating gluten |
| Medication absorption | Coffee, calcium, iron, some stomach conditions and celiac disease can all reduce how much levothyroxine you absorb.13 | If your TSH swings between tests, whether timing or absorption could be why |
| Another autoimmune condition | About 13.5% of people with autoimmune thyroid disease have a second one.14 | Any symptoms that don’t fit the thyroid picture |
| Sleep and mood | Depression and anxiety are more common in Hashimoto’s,15 and poor sleep can look a lot like thyroid fatigue. | Screening for sleep problems and mood, without it being used to dismiss you |
None of these rule out the immune explanation. You can have low ferritin and an active immune process at the same time. But iron, B12 and celiac disease have clear tests and clear next steps, which is more than anyone can offer for interleukin-1 right now.
Why we care about this one
Annesse, Kristin’s mom and the other half of the “we” on this site, didn’t have Hashimoto’s. It started in the summer of 1992 with exhaustion she couldn’t explain, and over the next few years she spent most of her time in bed, some days unable to wash her own hair. It took years, and more than one doctor, before she had names for it: lupus, then fibromyalgia and chronic fatigue syndrome.
Fatigue is easy to wave away because it doesn’t show up on a scan. If we could go back, we’d have kept a record from the first month: how tired, what time of day, after what. A single bad afternoon is easy to dismiss in a 15-minute appointment. Six weeks of notes is much harder to ignore.
Questions to bring to your doctor
- My TSH and T4 are in range, but I’m still exhausted. What other causes of fatigue have we ruled out, and could we check ferritin and B12?
- Should I be tested for celiac disease before I change what I eat?
- Is there a reason to check my free T3, or to look at when and how I take my levothyroxine?
- Since early research suggests inflammation may play a part in Hashimoto’s fatigue, how should we track my fatigue over time, separately from my thyroid numbers?
What we still don’t know
Nobody has shown that lowering interleukin-1 activity improves Hashimoto’s fatigue. The heat shock protein finding ran in the opposite direction from a similar study in Crohn’s disease, so it may not hold up. The surgery trial needs repeating in a blinded design, which is hard to do with surgery. Larger studies that follow people over time are the next step.
In Hashimoto’s, normal thyroid numbers and normal energy aren’t always the same thing, and being tired with good labs doesn’t mean you’re imagining it.
Quick answers
Does a normal TSH mean my Hashimoto’s is under control?
It means your hormone supply looks adequate from the blood. It doesn’t tell you whether the autoimmune process is active, and it doesn’t rule out other causes of fatigue.
Do higher TPO antibodies mean more fatigue?
Not clearly. In the 2026 Norwegian study, TPO antibody levels weren’t linked to fatigue at all. Earlier studies are mixed.
Will adding T3 fix the tiredness?
On average, studies haven’t found that adding T3 beats T4 alone for fatigue. Some people prefer it, so it’s worth discussing with your doctor, but it isn’t a reliable fix.
Should I ask about having my thyroid removed?
Surgery is not a first-line option. One trial in a specific group of patients with very high antibodies saw improvement, but it wasn’t blinded and surgery has real risks. It’s a conversation for a specialist, not a starting point.
Sources
- Hollowell JG, et al. Serum TSH, T4, and thyroid antibodies in the United States population (1988 to 1994): NHANES III. J Clin Endocrinol Metab. 2002;87(2):489-499. doi.org/10.1210/jcem.87.2.8182
- Zhang H, et al. Persistent symptoms in euthyroid Hashimoto's thyroiditis: current hypotheses and emerging management strategies. Front Endocrinol. 2025;16:1627787. doi.org/10.3389/fendo.2025.1627787
- National Institute of Diabetes and Digestive and Kidney Diseases. Hashimoto's Disease (last reviewed June 2021). www.niddk.nih.gov/health-information/endocrine-diseases/hashimotos-disease
- Jensen CZ, et al. Association of DIO2 and MCT10 polymorphisms with persistent symptoms in LT4-treated patients in the UK Biobank. J Clin Endocrinol Metab. 2024;109(2):e613-e622. doi.org/10.1210/clinem/dgad556
- Millan-Alanis JM, et al. Benefits and harms of levothyroxine/L-triiodothyronine versus levothyroxine monotherapy for adult patients with hypothyroidism: systematic review and meta-analysis. Thyroid. 2021;31(11):1613-1625. doi.org/10.1089/thy.2021.0270
- Capuron L, et al. Neurobehavioral effects of interferon-alpha in cancer patients: phenomenology and paroxetine responsiveness of symptom dimensions. Neuropsychopharmacology. 2002;26(5):643-652. doi.org/10.1016/S0893-133X(01)00407-9
- Dantzer R, et al. From inflammation to sickness and depression: when the immune system subjugates the brain. Nat Rev Neurosci. 2008;9(1):46-56. doi.org/10.1038/nrn2297
- Omdal R, et al. Interleukin-1 receptor antagonist and heat shock protein 90alfa are independently associated with fatigue and general health in euthyroid Hashimoto's thyroiditis. Front Endocrinol. 2026;17:1862441. doi.org/10.3389/fendo.2026.1862441
- Guldvog I, et al. Thyroidectomy versus medical management for euthyroid patients with Hashimoto disease and persisting symptoms: a randomized trial. Ann Intern Med. 2019;170(7):453-464. doi.org/10.7326/M18-0284
- Gierach M, et al. Iron and ferritin deficiency in women with hypothyroidism and chronic lymphocytic thyroiditis: systematic review. Endokrynol Pol. 2024;75(3):253-261. doi.org/10.5603/ep.97860
- Benites-Zapata VA, et al. Vitamin B12 levels in thyroid disorders: a systematic review and meta-analysis. Front Endocrinol. 2023;14:1070592. doi.org/10.3389/fendo.2023.1070592
- Roy A, et al. Prevalence of celiac disease in patients with autoimmune thyroid disease: a meta-analysis. Thyroid. 2016;26(7):880-890. doi.org/10.1089/thy.2016.0108
- Virili C, et al. Gastrointestinal malabsorption of thyroxine. Endocr Rev. 2019;40(1):118-136. doi.org/10.1210/er.2018-00168
- Botello A, et al. Prevalence of latent and overt polyautoimmunity in autoimmune thyroid disease: a systematic review and meta-analysis. Clin Endocrinol. 2020;93(4):375-389. doi.org/10.1111/cen.14304
- Siegmann EM, et al. Association of depression and anxiety disorders with autoimmune thyroiditis: a systematic review and meta-analysis. JAMA Psychiatry. 2018;75(6):577-584. doi.org/10.1001/jamapsychiatry.2018.0190
How we made this article. We start from the research behind our video, draft with help from AI writing tools, and check every number and claim against the original papers listed above. Last fact-check: October 13, 2026. Spot an error? Tell us on any of our channels and we’ll fix it.
This article is education, not medical advice. It doesn’t diagnose or treat any condition. Talk to your doctor before changing your care, and never stop or change a medication on your own.