Major Revision Possible in Guidelines for Diagnosing and Treating Hypothyroidism

In a suprise announcement a prominent leader in the field of thyroid disease, Dr. Leonard Wartofsky, suggested that a new lower level of TSH be utilized when attempting to evaluate and treat hypothyroidism.

When diagnosing hypothyroidism (low thyroid function) most physicians are trained to obtain a TSH measurement. TSH (thyroid stimulating hormone) is produced by the pituitary gland not the thyroid. The pituitary’s job is to act like a thermostat regulating the amount of thyroid hormone in the blood. When the pituitary senses thyroid hormone deficiency this “master gland” releases TSH into the blood to stimulate the thyroid to make more thyroid hormone. TSH therefore increases when thyroid hormone levels are low.

According to good medical training, it is appropriate to diagnose hypothyroidism and give thyroid hormone replacement only if the TSH level is above normal. The normal TSH level is generally recognized to be between 0.4 up to 4 or 5 (microIU/ml) depending on the lab where the assay is done.

I have found that relying strictly on the normal TSH range may fail to render a correct diagnosis of hypothyroidism. Take the situation in which an individual’s TSH level a year ago was 1.0 but this year is 2.8. Both of these TSH levels are within the normal range. Hasn’t something changed, however? Why is the pituitary releasing more TSH this year? My thought is in this situation the pituitary is sensing thyroid hormone deficiency and is trying to compensate by releasing more TSH. In such a case it may be appropriate to try thyroid hormone supplementation if there are also complaints compatible with low thyroid function.

The major flaw in the TSH measurement stategy is to fail to recognize how much variation in thyroid function can be hidden within the TSH normal range. To explain this I like to use the analogy of shoe sizes (you heard it here first!). It is common knowledge that although most people have normal foot size, only one shoe size is appropriate for each person. Similarly with TSH, for each individual there is very likely to be a particular level that is the “best fit”. Recall the normal TSH range is between 0.4 and 4.5. This is equivalent to a normal range of shoe size from 4 to 45! How difficult is it then to find the “best fit”?

For years, endocrinologists have debated what level of TSH is appropriate for the diagnosis of hypothyroidism. In a suprise announcement Dr. Wartofsky from Washington Hospital Center suggested lowering the upper limit of TSH to 2.5 (microIU/ml). This was after an analysis showed that 97% of the population had TSH levels below 2.5. In comparison the official American Association of Clinical Endocrinologists (AACE) statement recognizes the upper normal limit as 5.0, although dissenting members of this organization have been using 3.0 as the upper limit. By recognizing that a TSH level of 2.5 may signify thyroid hormone deficiency, Dr. Wartofsky and his colleagues legitimatize treatment with thyroid hormone replacement for a much broader range of patients then ever before. Public action groups have for years been seeking this reform in the medical community’s method for diagnosing and treating thyroid hormone deficiency.

My comments are intended as informational only, not to diagnose and treat medical conditions. Consult your own physician for individual advice on diagnosis and treatment of medical conditions.

Gary Pepper, M.D. Editor-in-Chief,

Share this post

  • gina

    I found that Dr. Wartofsky has been recommending a TSH upper level of 2.5 since at least 2005. “The Evidence for a Narrower Thyrotropin Reference Range Is Compelling”

    Unfortunately, the prestigious and influential Mayo Clinic as recently as January of this year issued “Subclinical Hypothyroidism: An Update for Primary Care Physicians” . Apparently, doctors can earn one CME credit by absorbing the following educational pearl: “Initiating levothyroxine replacement therapy is recommended for all patients with a TSH greater than 10 mIU/L … However, treatment of patients with a serum TSH level between 5 and 10 mIU/L remains controversial.”

  • Dr. Gary Pepper


    Thanks for the heads up about the Mayo Clinic guidelines. I have found that the “brand” medical institutions tend to use trainees to write many of their reviews and pronouncements. These employees rehash textbooks or previous reviews from the same institution perpetuating a cycle of out of date information. Their logos on these writings gives them authority in the general community. I only hope that not many docs are managing their practices using this type of material.

    It is easier to follow the pack mentality, particularly in the liability conscious medical community. I have to congratulate Dr. Wartofsky for sticking to his guns over the years since he is probably regarded as a radical by most of his peers for using new standards when evaluation thyroid function tests.

    Gary Pepper, M.D.

  • Amy

    I think the TSH needs to be discarded completely as a screening tool for hypothyroidism (as well as a treatment gauge). Symptomatic patients need to have their free T3 and T4 drawn to see how much hormone is actually circulating in their bloodstream as well as antibody tests for hashimoto’s. TSH can be any number, as was evidenced by myself for many years. I had a recent TSH of 1.65 while my T3 was below range and my T4 was 40% of range. Obviously if my TSH was the only tool used to screen me I would be told my thyroid was “normal”… now how bout we put you on an SSRI and prescribe some NSAIDs for those joint pains… and here’re some laxatives and how bout some Lyrica for those Fibro symptoms? I know you’re bucking a big tide here Dr Pepper but I would hope that Endos would finally figure out that TSH is useless for many of us (millions by some estimates).

  • Diana

    A patient experiencing symptoms of thyroid sluggishness despite a “normal” TSH should be tested right away for anti-thyroid antibodies. This will save the patient from suffering more than they already are.



  • Amy

    Diana, I’ve been repeatedly tested for antibodies and they’ve always come back normal . But my free T3 and free T4 were below or at the low end of range. So either the antibody tests have very poor sensitivity or I just don’t have them and am simply hypothyroid.

    Wanda: you are an excellent person to consider going over to natural thyroid hormones. I suggest Stop the Thyroid Madness website if you are interested in learning more.

  • Leslie

    What about the acceptable “lower level” of the range? I have a feeling that after my most recent medication increase, my TSH is going to make me look hyperthyroid – but I feel good….actually pretty great. I feel better than I have anytime in the previous 4 years! There is no way I will want to back off of the medication.

    Can anyone offer some way for me to help my doctor “get it?”

  • Sue

    My levels before were 4.1 and now at 1.75

  • Amy

    Leslie, we aim for high levels of T3 and T4 but a suppressed TSH. Most doctors see the low TSH and assume we are hyper.

    All I can say is tell your doc you feel fine and that you are very well aware what the symptoms of hyperthyroidism are and you will tell him if you have any.

    The hard part for many of us is when we are still hypo and working our way up to a therapeutic level and a doctor sees a low TSH and wants to stop or reverse treatment. This seems to happen all the time. I recently saw my doc’s NP and she told me I had to back off my meds because my TSH was below 1. I just assured her that I was still somewhat hypo and that I was well aware of what hyper symptoms were. I convinced her but not every practitioner is going to be that easy.

  • Leslie

    Any – I’m gearing up for my next appointment with my doc. Once in the past he became concerned that I would be hyper and had me back off my meds a bit. The result was pretty bad. I gained back the small amount of weight that I had lost, and pretty quickly developed bad hypo symptoms again. I recently convinced him, in spite of a TSH of around 1.9 that I was under-medicated. So he reluctantly increased my meds. Not I feel really good again. In fact, I feel like myself again. I feel happy again, and my moods are more steady. I have good energy again. I’ve lost 20 lbs over the last 5 months. I have NO hyper symptoms at all. It’s hard to argue with such success. I have a great doc who really listens and trusts my assessment of how I’m doing. I hope he will see that the numbers don’t mean much – how a patient feels is really what counts.

  • Theresa

    I find it odd that on all the thyroid forums I have seen, not one mentions the risk of cardiovascular fatality due to under medication of hypothyroidism.

    In 1988 I had radioactive iodine ablation therapy and was euthroid for 8-years. Diagnosed in 1996 as hypothyroid. Prescribed Synthroid and have never felt well.

    On Synthroid, my TSH, Free T3, and Free T4 are in the normal range, with a myriad of continued hypothyroid symptoms… My new doctor ordered a Reverse T3 test. All levels look ok except my Reverse T3 level is 399 pg/mL. The Reverse T3 reference range: 90 to 350 pg/mL.

    Due to the prescribed non-treatment (Synthroid) of my hypothyroidism, I have become deficient in Vitamin B12, B6, Folate, and Vitamin D. All of which are required for cardiovascular health. The result is that my homocysteine levels are off the charts.

    The high sensitivity C-reaction protein test (hs-CRP) test measures homocysteine (inflammation of arteries). The high-sensitivity CRP test (hs-CRP) is done to find out if you have an increased chance of having a sudden heart attack or stroke.

    Inflammation can damage the inner lining of the arteries and make having a heart attack more likely. Multiple studies now show that elevated C-reactive protein (CRP) levels are correlated with increased risk of cardiac events and mortality.

    CRP Levels: Low Vitamin B and Elevated Homocysteine:

    There is a correlation that the lower the vitamin B levels the higher the homocysteine levels. High homocysteine levels are linked to damage to the arteries, which can cause atherosclerosis and thrombosis.

    There is also a link between low Vitamin D and cardiovascular disease.

  • Amy

    Theresa, the thyroid forums I’m on I am always pushing the connection between inadequate thyroid treatment and heart disease.
    There is a very good Norwegian study called the HUNT study that indicates that a TSH above 1.4 significantly increases the risk of heart disease and death in women. Their conclusion:
    “Thyrotropin levels within the reference
    range were positively and linearly associated with Coronary Heart Disease (CHD)
    mortality in women. The results indicate that relatively
    low but clinically normal thyroid function may increase
    the risk of fatal CHD.”
    While low TSH is not a good indication of how hypothyroid we are, any increase in TSH (and by increase I mean levels over 1) is often a very good indication that the body is suffering from inadequate thyroid activity.