Low T3. Haven't been diagnosed yet. What could this be?

The normal range for TPOab is 0-150 so my TPOab is well within the range.

Hi Stan, how brilliant of you! I've been reading posts here for three years and yours is a very unique approach- thanks for sharing! You are very much on track with diet changes, as thyroid disease is autoimmune disease. I've addressed your many questions from my own experiences and hope you find them useful. I greatly appreciate your post, as you've included so much thoughtful information as well as the athletic perspective. 

This is could very well be hypothyroidism as thyroid disease, in addition to being autoimmune disease, thyroid disease is associated with heart disease, gut disorders, and mood, to mention a few things. When my thyroid disease was at its worst, my BP was extremely low. Panic attacks, anxiety and irregular heart beats, palpitations are also associated with thyroid disease. Both high and low T3 relative to T4, or true low or high T3 can result in anxiety and palpitations- more towards T3 being intimately connected with adrenal function. So it's likely you have adrenal exhaustion, or some other adrenal imbalance that the thyroid is trying to compensate for. This is something worth looking into because adrenal and thryroid functions work together along with insulin to maintain metabolic homeostasis. You could find that the training is over stimulating the adrenals, and the T3 levels drop in lieu of high adrenalin or cortisol levels, for example. So good adrenal health goes a long way towards good thyroid health. With adrenal problems, you may see hormone levels drop.

I love your healthy approach! Other dietary changes for good thyroid health include a strict gluten-free diet, and paleo style diet of high protein, high veggies, no grains. Substitute root vegetables for grains. No soy, refined sugar or dairy. You'll find yogurt and hard cheeses to be the exception to the dairy rule because the aging reduces lactose and casseine allergens. Miso is the exception to soy for the same reason.

T4-T3 conversion happens greatly in the liver and gut, so these organs must be given extra care with thyroid disease. I've found essential amino acids to be incredibly helpful for thyroid health, as well as for gut health. I feel that a high protein diet is essential to thyroid health, and supplements with protein powder or amino acids can likely contribute to remission of thyroid disease.

T3 is the fast acting, short lived thyroxin, and is likely boosted with adrenal and other stress. Because running very specifically is known to be related to adrenal response, and in fact running is known to complete the adrenal cycle and turn off the stress response, your marathon training may be related. Since thyroid patients often become so sluggish, they can hardly exercise (further worsening health), it's unusual to see a post such as yours.

I was an athlete as a teen and feel I had hypothyroid onset during the increase in competitiveness and intensity of my athletic training, although it was never diagnosed because in athletes, you rarely see the extreme weight gain symptoms you see in other thyroid patients. Over the years, my thyroid disease has gone through many stages of ups and downs, and worsening time periods coincide with extreme stress, toxicity, grief, chemical and radiation exposure, poor diet and other factors. I feel the stress of athletic training can both help and worsen thyroid disease, though my guess is it's the extreme overtraining that can contribute to thyroid dysfunction, while the  "normal" high intensity training seems to help get thyroid issues back on track. The topper is that low thyroid can then result in a higher load on the body during training- you see the problem of how this can result in a vicious cycle. Still high activity is far preferred in any stage of thyroid disease. My point is that you might want to consider you could be overtraining. 

As as for detoxing, RIGHT ON! Yes, I've had excellent success with liver and colon cleansing. And in fact, my experience has been that these are crucial for good thyroid health.

Another note, you might find useful is that my cholesterol, usually low, shows high levels with early thyroid problems and seems to parallel thyroid symptoms, and cholesterol spikes for me have been an early warning sign. I actually find cholesterol to be a better indicator for me than TSH levels.

Have you had a thyroid ultrasound? This might be useful. Thyroid disease is often hidden in athletes. Hashimoto's doesn't always show up with blood tests and can also be diagnosed via ultrasound by the appearance of cysts on the thyroid.

Hi Stan, the antibody tests are notoriously inaccurate, with a 50% false negative. So basically the antibody tests are useless if you have a negative result. Your reduced histamine diet would likely help reduce antibodies. 

For or people who appear to have thyroid disease but it doesn't show up in blood work or other tests, an ultrasound will show whether there is any abnormal growth, which would indicate a diagnosis.

Finally, the "normal" ranges provided labs are not necessarily normal, as my experience is that a TSH of 2 or higher can indicate hypothyroidism. A good endocrinologist uses more narrow and precise ranges for diagnosis than the lab ranges. This is one reason people can go decades with full on thyroid disease without a diagnosis.