Normal Thyroid? Maybe Not.



Normal ThyroidQUESTION: Dear Dr. Sievers and Coach Karen,
I am a 39 year old female trying to lose weight. I eat a healthy diet and exercise at least 45 minutes, five times a week, but the scale won’t budge. I also notice that I have no energy, am often cold, awaken with leg cramps and have brittle nails. Worst yet, my libido is low; sleep just sounds so much better than sex! I had a recent thyroid test and was told it was normal. What do you think?

ANSWER: Thyroid is one of my favorite topics. Although it is not the remedy for weight loss, the thyroid can play a critical role in assisting it. Certainly your symptoms are classic for an underactive thyroid or hypothyroidism, but like many patients, the tests came back normal. More than likely your doctor only tested your TSH levels. And therein lays the problem: testing TSH levels alone will not provide an accurate diagnosis of thyroid function. But because it is relatively inexpensive, and TSH labs are prevalent, TSH testing has unfortunately become common practice.

I meet patients all the time who have been suffering with symptoms of hypothyroidism for years because their doctor only tested their TSH levels. But the thyroid is a very complex system, and requires the critical analysis of many factors in order to make a proper diagnosis. A brief understanding of the thyroid will help shed some light.

Located in the front of the neck, the thyroid is a small organ that produces several thyroid hormones which help to affect very specific body functions. The thyroid hormones help control energy levels, digestion, metabolism, body temperature regulation, sexual function and much more.

The hormones produced by the thyroid are T4 (thyroxine), T3 (triiodothyronine), and T2 (dioodothyronine). And in order to stimulate those hormones, the brain releases TSH (thyroid stimulating hormone). Once adequate T4 is produced, the thyroid signals the brain that enough T4 has been made and to stop or decrease the production of TSH. Therefore, in theory–and I can’t stress this enough because it is not always reflected clinically–the lower the TSH then the more production of T4 and thus the more active the thyroid.

However, it’s not that simple. First one needs to understand that for the thyroid hormones to have an effect in the body they must search for receptors that act as a key hole for that specific hormone and subsequently release it. And while 80% of the hormone released and made in the thyroid gland is T4, it must convert to T3 in order to bind to its receptor making T3 five times more active than T4.

But it gets a bit more complicated; the T4 hormone not only converts into T3 but also into reverse T3 and blocks the binding of the much needed T3 to the thyroid hormone receptor. If reverse T3 levels are high, it means that T3 will be lower and have less ability to interact with the thyroid receptor causing your thyroid to function improperly and for you to feel lousy. At the same time, however, your TSH may remain low and your doctor will say your thyroid is normal. But in actuality you have hypothyroidism causing you feel to suffer from the symptoms you described. . (There are also antibodies that one can make which also affect the interaction of T3 with the receptor and thus affect thyroid function but that is beyond the scope of this discussion.)

There are a multitude of causes for thyroid dysfunction ranging from hormone imbalances, vitamin deficiencies, improper diet and even food allergies. But stress can also play a large role, directly affecting the release of TSH. In other words, you may have a very low TSH because the release was decreased by stress.

The conventional treatment for hypothyroidism is T4, thyroxine which is commercially known as Synthroid. However, T4 has never proven to be effective for treating the symptoms of hypothyroidism in any long term study. But frequently I see patients still complaining of hypothyroid symptoms while on Synthroid with ‘normal’ tests. In those cases I either add T3 or change to porcine based thyroid such as Armour and patients feel better.

This is just a short explanation of the thyroid hormone. Clearly having a low thyroid can have numerous implications with how you feel. The take home points are that you can have an underactive thyroid with a ‘normal’ TSH and that T4 alone is not always the answer for replacement. The T3 must also be evaluated. As always, nutritional deficiencies and hormonal imbalances affect the thyroid.

In your particular case, I would want to have more comprehensive thyroid tests taken to see if a low thyroid is the cause of your symptoms. If it was low then measuring iodine and other nutrient levels are important to know in order to assess the cause. Working with Karen would help you balance your diet to get the proper nutrients.

All information contained herein is the opinion of the writers. It is intended to provide helpful and informative material on the subjects addressed and is not meant to malign any pharmaceutical or, nutraceutical company, medical profession or organization. Readers should consult their personal physicians before adopting any of the recommendations or drawing inference from information contained herein. The writers specifically disclaim all responsibility for any liability, loss, risk — personal or otherwise — incurred as a consequence, directly or indirectly, from the use and application of any material provided.

Teresa A. Sievers, MD
Restorative Health & Healing Center
10201 Arcos Av., Suite 201, Estero
Learn more about Dr. Sievers at:

Karen R. Callan, CHC, AADP
Certified Health Coach
10201 Arcos Ave., Suite 201 Estero
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