Endocrine Society
endocrine.org › patient-engagement › endocrine-library › hashimoto-disease
Hashimoto Disease | Endocrine Society
March 31, 2022 - A low level of free T4 and/or T3 test also suggest hypothyroidism. Thyroid Peroxidase (anti-TPO) Antibody Blood Test: This test detects the presence of antibodies directed against the thyroid.
PubMed Central
pmc.ncbi.nlm.nih.gov › articles › PMC6442890
Transient T3 toxicosis associated with Hashimoto’s disease - PMC
Our patient presented with high levels of free T3 and normal levels of free T4, along with suppressed levels of TSH, consistent with T3 toxicosis. The patient tested positive for elevated thyroid peroxidase and thyroglobulin antibodies, confirming Hashimoto’s thyroiditis.
Videos
Cleveland Clinic
my.clevelandclinic.org › health › diseases › 23903-subclinical-hyperthyroidism
Subclinical Hyperthyroidism: What It Is, Symptoms & Treatment
July 21, 2025 - If you had thyroid blood tests and the results indicate that your TSH levels are low or undetectable (0.1 to 0.4 mIU/L) and your thyroxine (T4) and triiodothyronine (T3) levels are in the normal range, it means you have subclinical hyperthyroidism.
Paloma Health
palomahealth.com › learn › treatment-hashimotos-normal-tsh
Treatment For Hashimotoʼs With Normal TSH Levels | Paloma Health
August 27, 2024 - A normal TSH and T4 level means your thyroid still functions well, and the body is not suffering from a lack of thyroid hormone. Thus, there is no need to add extra thyroid hormone to the body.
Reddit
reddit.com › r/hashimotos › low tsh and low t3. doctor is stumped
r/Hashimotos on Reddit: Low TSH and low T3. Doctor is stumped
March 11, 2022 -
I was first diagnosed with hypothyroidism a year ago with a high TSH. I was put on 25mcg levo. First check up was fine and was told to continue taking the pills, second in may showed that my tsh was not detectable. Doctor told me to stop taking my pills and I did. For the next 2 months it kept being non detectable until last time where it got bumped up to like 0.03. She still doesn't know why it's that low when my low T3 is showing that I'm hypo.
She told me to wait 3 months without meds before going back for another test. She told me there's no reason for it to keep being low and she said I'm a medical phenomenon
Could something else be the cause for the low TSH? Maybe even something non related to the thyroid?
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You have central and/or "secondary hypothyroidism". This is the hallmark of secondary hypothyroidism. Low TSH with low free t4 and low free t3. I have the same and i believe my medication is causing it (quetiapine). Find a more experienced endocrinologist. I can't believe how many doctors are only looking at TSH. People with central hypo are being under treated and ignored.
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She told me there's no reason for it to keep being low and she said I'm a medical phenomenon You're not a medical phenomenon. This sounds like it could possibly be Central Hypothyroidism. TSH, thyroid stimulating hormone, is a pituitary hormone released by the pituitary gland in the brain. Central Hypothyroidism is a pituitary, hypothalamus, or pituitary and hypothalamus disorder. In Central Hypothyroidism, the pituitary gland does not release normal levels of thryoid stimulating hormone, and the thyroid does not release normal levels of thyroid hormone. You mention your T3 being low. Is this Total T3 or Free T3? T3 is the secondary thyroid hormone that is converted from T4. T4 is the primary thyroid hormone. What is your Free T4 level and the reference range? You mention your T3 is low. How low is it and what's the reference range?
UCLA Health
uclahealth.org › medical-services › surgery › endocrine-surgery › conditions-treated › thyroid › normal-thyroid-hormone-levels
Normal Thyroid Hormone Levels - Endocrine Surgery | UCLA Health
TSH normal values are 0.5 to 5.0 mIU/L. Pregnancy, a history of thyroid cancer, history of pituitary gland disease, and older age are some situations when TSH is optimally maintained in a different range as guided by an endocrinologist.
NCBI
ncbi.nlm.nih.gov › books › NBK459262
Hashimoto Thyroiditis - StatPearls - NCBI Bookshelf
November 30, 2025 - A majority of individuals with ... develop hypothyroidism.[75] ... These individuals present with symptoms of hypothyroidism, a TSH of more than 10 mIU/L, or low T4 and T3 levels....
Cleveland Clinic Journal of Medicine
ccjm.org › content › ccjom › 77 › 11 › 803.full.pdf pdf
Approach to a low TSH level: Patience is a virtue
T3 to assess T3 status. ... Central hypothyroidism. A low TSH ... Disequilibrium state = the period during the hypothyroid phase of thyroiditis in which the thyroid-stimulating hormone (TSH) level · transiently remains low or inappropriately normal in the setting of low levels of free thyroid hormones; T4 = thyroxine;
PubMed Central
pmc.ncbi.nlm.nih.gov › articles › PMC5922674
How to interpret thyroid function tests - PMC
For example, both fractionated and unfractionated heparin activate endothelial lipoprotein lipase with hydrolysis of triglycerides and an increase in circulating free fatty acid levels that, in some individuals, leads to displacement of T4 and T3 from TBG, thus raising free (but not total) TH levels. Interestingly, such changes are not generally associated with clinical thyrotoxicosis, and TSH is usually normal.
Mayo Clinic
mayoclinic.org › diseases-conditions › hashimotos-disease › diagnosis-treatment › drc-20351860
Hashimoto's disease-Hashimoto's disease - Diagnosis & treatment - Mayo Clinic
April 30, 2025 - The main thyroid hormone is thyroxine (T-4). A low blood level of T-4 confirms the findings of a TSH test and indicates the problem is within the thyroid itself. More than one disease process can lead to hypothyroidism.
American Thyroid Association
thyroid.org › home › hashimoto’s thyroiditis
Hashimoto’s Thyroiditis | American Thyroid Association
August 25, 2023 - you have symptoms of hypothyroidism, and a blood test shows an underactive thyroid gland [an elevated Thyroid Stimulating Hormone (TSH) level with or without a low thyroid hormone (free T4 or total T4) level]. you have enlargement of your thyroid ...
PubMed Central
pmc.ncbi.nlm.nih.gov › articles › PMC8122172
Persisting symptoms in patients with Hashimoto’s disease despite normal thyroid hormone levels: Does thyroid autoimmunity play a role? A systematic review - PMC
TSH, free T4 and free T3 levels were similar in HD patients and controls (non-autoimmune hypothyroidism and euthyroid benign goitre patients) in four studies [[19], [20], [21],31]. In two studies TSH values were significantly lower in the control groups [28,30], that consisted of patients who underwent thyroidectomy because of differentiated thyroid cancer and who were subsequently treated with LT4 aiming at a suppressed TSH [30]. In one study all HD patients and controls were classified as euthyroid, but thyroid function was not specified [29].
Medscape
emedicine.medscape.com › tools & reference › endocrinology
Hashimoto Thyroiditis Workup: Approach Considerations, Serum TSH Test and Other Studies, Ultrasonography
A low free T4 level in the presence of an elevated TSH level further confirms the diagnosis of primary hypothyroidism. When a total T4 study, rather than a free T4 study, is performed, a T3 resin uptake helps to correct the total T4 and T3 values for protein binding, especially thyroid ...
Better By Dr. Brooke
betterbydrbrooke.com › home › articles › ...
The Trouble With TSH (Especially When You Have Hashimoto's) - Better By Dr. Brooke
May 27, 2020 - Guess what else? Her TSH is also normal (because it is low total T4 that is the signal to her pituitary to make more TSH to stimulate the thyroid and T4 value is normal in this scenario).
University of North Carolina
med.unc.edu › home › podcasts › autoimmune thyroid disease – with deepa kirk, md
Autoimmune Thyroid Disease - with Deepa Kirk, MD | Department of Medicine
June 6, 2023 - Now the difficulty lies—if the patient is having symptoms, and everything is normal, the TSH is fine, T4 and T3 are fine–some practitioners are drawing another test called antibody tests—TPO antibodies.
Medical News Today
medicalnewstoday.com › articles › hypothyroidism-with-normal-tsh
Hypothyroidism with normal TSH: Causes and treatment
December 18, 2023 - This can indicate that their thyroid is beginning to work less efficiently. People with subclinical hypothyroidism can also have elevated thyroid antibodies, but typically, they do not have low levels of the thyroid hormones T3 or T4.
Mount Sinai
mountsinai.org › health-library › report › hypothyroidism
Hypothyroidism Information | Mount Sinai - New York
This global public health issue used to be even more widespread, but has now been almost completely resolved due to salt iodization programs. Too much iodine is a signal to inhibit the conversion process of T4 to T3. The end result in both cases is inadequate production of thyroid hormones. Some evidence suggests that excess iodine may trigger the process leading to Hashimoto thyroiditis.
Verywell Health
verywellhealth.com › hashimotos-disease-treatment-3233013
How Hashimoto's Disease Is Treated
October 9, 2025 - For people with subclinical hypothyroidism whose TSH falls in the 4.5 to 9.9 mIU/L range but who don't need levothyroxine, the ATA recommends close monitoring to check TSH and free T4 levels yearly.
American Thyroid Association
thyroid.org › home › thyroid function tests
Thyroid Function Tests | American Thyroid Association
June 8, 2020 - A low TSH and low FT4 or FTI indicates hypothyroidism due to a problem involving the pituitary gland. A low TSH with an elevated FT4 or FTI is found in individuals who have hyperthyroidism.
HealthCentral
healthcentral.com › condition › thyroid › thyroid-gland-function-tests
Interpretation of Thyroid Tests
June 1, 2020 - Normally, low levels (less than 5 units) of TSH are sufficient to keep the normal thyroid gland functioning properly. When the thyroid gland becomes inefficient, such as in early hypothyroidism, the TSH becomes elevated even though the T4 and ...