Is Your Thyroid Doctor Using the Old TSH Lab Standards?

What is TSH? TSH (thyroid stimulating hormone) is a thyroid test to diagnose thyroid disorders. High TSH is diagnosed as hypothyroidism, low thyroid problems.

Most conventional doctors rely on TSH as the gold standard to measure thyroid functioning. Many mainstream doctors do not run a full thyroid panel that should at least include Free T4, Free T3, Reverse T3, and thyroid antibodies. Unfortunately TSH alone does not provide a complete picture. If doctors are going to rely on TSH alone, however, they should at least give consideration to the controversy over the TSH normal reference range and consider this when diagnosing patients. Right? We are more than a lab number. It’s up to us to take control of our thyroid health and insist our doctors treat us the patient and not this controversial TSH lab number, even if they look at us like we are CRAZY for questioning them!

The thyroid gland is a little butterfly-shaped gland at the base of our necks. TSH stands for Thyroid Stimulating Hormone, a hormone produced in the pituitary gland in the brain that tells the thyroid how much thyroid hormone to make.

Typically, if there is a low level of thyroid hormone in the body, the pituitary will increase production of TSH to stimulate the thyroid to produce more thyroid hormone. Therefore a high TSH level suggests an underactive thyroid (hypothyroidism), while a low TSH indicates too much thyroid hormone in the body (hyperthyroidism).

In my post “Miscarriage in New York City…Be Thyroid Aware”, I outlined the TSH ranges for pregnancy and provided trimester-specific ranges. In this post I would like to discuss the normal TSH lab standards for non-pregnant adults.

Thyroid Stimulating Hormone

For many years, most mainstream doctors have considered TSH level >10 mIU/L evidence of overt thyroid failure, and levels of 5-10 mIU/L evidence of mild or subclinical hypothyroidism. Many doctors refuse to treat hypothyroidism if a person’s TSH is less than 5 mIU/L even when the patient presents with classic hypothyroidism symptoms. This strict reliance on 5 mIU/L has left many hypothyroid people suffering with debilitating symptoms and yet their doctors refuse treatment.

For over a decade there has been considerable debate about the correct upper limit of the reference interval for TSH. According to the old standards 5.0 mIU/L is the upper limit. This upper number is critical in determining who is diagnosed with hypothyroidism and who is not.

Modern medicine continues to argue within itself on the proper upper limit of the reference range for TSH.

One of the largest studies of thyroid problems in a population is the Whickham Survey, which studied the thyroid levels of 2,779 randomly selected adults living in the town of Wickham in England from 1972-1973 and subsequently followed for 20 years. Data from the twenty-year follow-up published in 1995 demonstrated an increased risk for the development of hypothyroidism once TSH exceeds 2.0 mIU/L.[1. Vanderpump, M.P., Tunbridge, W.M., French, J.M., Appleton, D., Bates, D., Clark, F., Grimley Evans, J., Hasan, D.M., Rodgers, H., Tunbridge, F. The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey. Clin Endocrinol (Oxf) 1995 Jul;43(1): 55-68]

The third National Health and Nutrition Examination Survey (NHANES III) screened 17,353 subjects from 1988 to 1994 and excluded those with diseases or factors known to affect thyroid function. In the resultant ‘normal’ population of 13,344 subjects, 95% had TSH levels that fell between 0.3 and 2.5 mIU/L.[2. Hollowell, J.G., Staehling, N.W., Flanders, W.D., Hannon, W.H., Gunter, E.W., Spencer, C.A., Braverman, L.E. Serum TSH, T4, and thyroid antibodies in the United States population (1988 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrinol Metab 2002 Feb;87(2):489-99],[3. Lee, S.L. When is the TSH normal? New criteria for diagnosis and management. Lecture presented at 12th Annual Meeting of the American Association of Clinical Endocrinologists (AACE), San Diego, CA, May 14, 2003 (]

These findings supported the establishment of a narrower TSH reference range and a lowering of the upper limit of the range.

The National Academy of Clinical Biochemistry (NACB) in 2002 recommended that the upper limit of the reference range be lowered:[4. National Academy of Clinical Biochemistry 2002. Laboratory Medicine Practice Guidelines: Laboratory Support for the Diagnosis and Monitoring of Thyroid Disease. Retrieved from:]

The recent follow-up study of the Whickham cohort has found that individuals with a serum TSH >2.0 mIU/L at their primary evaluation had an increased odds ratio of developing hypothyroidism over the next 20 years, especially if thyroid antibodies were elevated.

In future it is likely that the upper limit of the serum TSH reference range will be reduced to 2.5 mIU/L.

In 2003, the American Association of Clinical Endocrinologists issued a press release in support of lowering the upper limit of the reference range:[5. American Association of Clinical Endocrinologists (January 2003 Press Release). Over 13 Million Americans with Thyroid Disease Remain Undiagnosed. Retrieved from:]

Until November 2002, doctors had relied on a normal TSH level ranging from 0.5 to 5.0 to diagnose and treat patients with a thyroid disorder who tested outside the boundaries of that range. Now AACE encourages doctors to consider treatment for patients who test outside the boundaries of a narrower margin based on a target TSH level of 0.3 to 3.0. AACE believes the new range will result in proper diagnosis for millions of Americans who suffer from a mild thyroid disorder, but have gone untreated until now.

However in 2012, the Clinical Practice Guidelines for Hypothyroidism in Adults: Cosponsored by the American Association Of Clinical Endocrinologists and the American Thyroid Association recommended 4.12 as the upper limit of normal for TSH.[6. Clinical Practice Guidelines for Hypothyroidism in Adults: Cosponsored by the American Association Of Clinical Endocrinologists and the American Thyroid Association. Retrieved from:] (Wait! What happened to the AACE’s press release in 2003 to reset the TSH level to 0.3 to 3.0? Do you see the craziness of all this?)

Thyroid Advocacy To Lower The Upper Limit of TSH

Thyroid advocates and many integrative physicians are fighting to narrow that range. Thyroid doctor Dr. Weston “Wiggy” Saunders posted this important message on his Dr. Wiggy Thyroid MD Facebook page.

Dr. Wiggy TSH 1.5

Thyroid advocate Mary Shomon, from the Thyroid Disease website, shared this important list of recommended lab tests and optimal ranges on her Thyroid Support Facebook page. Note the optimal TSH range listed.

Mary Shomon optimal thyroid lab ranges

When I was initially diagnosed with hypothyroidism after the birth of my first son in 2006, I listened to my doctors unquestioningly. I assumed that my doctors were the experts and that they knew everything there was to know about this disease. My doctor was using the old 0.5 to 5.0 TSH lab standard and kept telling me my TSH was normal falling in this range, yet I felt awful. Under my doctor’s care my TSH levels rose to 10.0 mIU/L.

At a TSH of 4.0 I felt sick and tired. By the time my TSH rose to 10.0, I felt like the walking dead struggling to make it through each day.

I even had one doctor who said she only treated a person for hypothyroidism when their TSH rose above 10.0 otherwise it was unnecessary. WHAT?!! I couldn’t function at a TSH of 10. I couldn’t get up from my bed to take care of my young son.

What Should You Do?

What if you have many symptoms of hypothyroidism, but your doctor is testing TSH only and your TSH is “normal”. What should you do?

What if you are being treated for hypothyroidism but you still suffer symptoms and your doctor is insisting your treatment is fine because your TSH is “normal”. What should you do?

Don’t just accept “your thyroid is normal” from your doctor. Insist on a full thyroid panel not just TSH but also Free T4, Free T3, Reverse T3 and thyroid antibodies. Get a copy of your lab results and check your scores yourself, even if your doctor acts like you are crazy (because you are NOT)!

I’m thankful that I found a great doctor who understands that I am more than my lab numbers. My doctor listens to me and my symptoms and for this I am grateful. TSH is only a number and it doesn’t give an accurate picture of my thyroid health. There are people like me on thyroid medication who feel our best when our TSH is below the ‘normal’ range. I feel fabulous with a suppressed TSH without signs of over-medication.

If I had a doctor that looked at TSH alone, I would be a very ill woman today.

If your doctor won’t do the additional tests and insists on relying on TSH while you suffer symptoms, find a new doctor. Find a doctor who understands you are more than a lab number. There are good thyroid doctors out there. Here is a list of resources to help you locate a great thyroid doctor in your area.

Do NOT settle.


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About Dana Trentini

I founded Hypothyroid Mom October 2012 in memory of the unborn baby I lost to hypothyroidism. Hypothyroid Mom is for informational purposes only and should not be considered a substitute for consulting your physician regarding medical advice pertaining to your health. Hypothyroid Mom includes affiliate links to favorite resources including the Amazon Services LLC Associates Program. Connect with me on Google+


  1. My tsh goes from 3.5-3.8. I feel so tired. My joints hurt. My belly is getting bigger but my arms and legs stay super small. Absolutely no sex drive. I feel depressed. And am actually getting treated for depression. I am a male in 30s. I have paternal grandmother with hypothyroidism. Would levo help me feel normal. I need help I’m just so lazy and tired feeling and moody I feel like I’m a horrible dad…single dad.

    • Hi Thomas,
      So sorry to hear about this, I had the same problem. My doctor did reluctantly put me on Levo when I got to 3.9 although it really didn’t work for me. After reading through a lot of websites and doing my own research, I found out about Thyrogold (on sttm) and I decided to stop taking the Levo and give it a try. I am still trying to find the correct dose as I went to the doctor yesterday and my TSH is currently .01 which is too low. I do feel amazing and I’m not having a hard time sleeping or anything, if my test results would not have been low I would have thought I was in a normal range. When I decided to look into getting Natural Dessicated Thyroid on my own was the last time I saw the doctor in July my blood pressure was 86/49 and my heart rate was 49, they wouldn’t let me leave before giving me an EKG. Not to mention I felt horribly tired from morning until night and just overall terrible. Hope all works out well for you

  2. Hi There,

    I just got these labs from my endocrinologist and I wanted a different perspective on them.

    Can you tell me your thoughts?

    I am a 47 year old Lebanese female who is “5” ‘4 3/4″ and weighs 169 lbs. I have lost 46 lbs since last December 19, 2015.

    I have PCOS and genetically inherited high cholesterol and high blood sugar. Besides genetics I am a sugar addict and have binge eating disorder.

    I have been pre diabetic off and on for at least 5 years. I have never been diagnosed with diabetes as I have never reached diabetic numbers through a self induced OGTT, A1c tests, fructosamine and fasting blood sugars.

    I am working on my diet and exercise to reduce certain blood markers.

    My blood sugar has come down and I am still working on my cholesterol. The cholesterol was measured by my primary care doctor and cardiologist.

    The blood work below was from last week at my Endocrinologists office.

    My last total cholesterol was 360 but my hdl and triglycerides were in normal range. Taken about a couple months ago.

    Last spring my total cholesterol was 259 coming down from 312. Prior to 312 it was 344.

    When it was 259 my hdl and trigs had also improved.

    I think it went high again because I started eating sugar again. I was still losing weight and monitoring my caloric intake but I went Paleo almost sugar free from December 2015 to April 2016 and that’s when my cholesterol came down from 312 to 259.

    I am back to minimizing sugar intake.

    I also suffer from depression, anxiety and ocd.

    I started gaining weight when I hit puberty and developed PCOS. I have lost and gained weight many times since then.

    I carry most of my weight in my belly.

    I am having a hyperoscopy done on Dec 15. Some hyperplasia was found in my uterus.

    I have never had kids. My period has been regular since my early thirties.

    Please let me know if you need any more information.

    I appreciate your insight!!

    Thank you very much.




    T3, Free: 2.6

    TSH: 2.33



    Fructosamine: 243

    A1C: 5.4



    Insulin: 3.8


    C-PEPTIDE: 1.31

    Vitamin D: 25

    SODIUM 137
    CHLORIDE 103
    GLUCOSE 92
    Bun/Creatinine ratio is not reported when the BUN
    and creatinine values are within normal limits.

    CALCIUM 9.9
    ALBUMIN 4.2
    A/G RATIO 1.4 1
    AST 12
    ALT 13

    Fasting reference interval


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  5. Katy Marie Burns says:

    I am a 65 yr old female and I was diagnosed 6 months ago with hypothyroid. I was given 25mg levothyroxine at first and later increased to 50mg. In 6 months I put on over a stone and a half in weight and my joints ached unbearably, diff sleeping, hot and cold flushes, headaches and tiredness continually. I stopped taking my thyroid tabs had another blood test and there was no difference in the reading. So taking the tabs and weight increase ++ was all for nothing! My reading was/is TSH 5.37. I cannot bear the thought of staying on the tabs and getting even fatter and not sleeping etc. Any advices would be greatly appreciated. Thanks, Katy

  6. My tsh came back 3.5 with a borderline ldl of 138. I am 35, 5 feet tall 133 lbs and all the weight on my stomach. I am constipated all the times, cold when everyone else seems fine, losing hair and have gained weight in last year and regardless of how healthy i eat and how much I exercise it doesn’t change. I am also irritated all the time. I am pretty sure my doctor will say it’s normal as when i told her i want to get my thyriod checked she said well if its not thyriod we have to work on your diet. I am sick of eating nothing and worrying about my weight all the time.

  7. Thanks for posting ur experience. Mine is 5.2 and they want me to take that xact dose! The reckless doctors at the VA didn’t even listen to me. I am reluctant to suffer your dilemma as I believe there r many factors especially Stress and life style change. I also see this was my reading in 2011! Obviously more complex testing or gradually stopping the meds if they are harming u!

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