The function of your thyroid is central to your overall well-being. Every cell in your body and brain needs thyroid hormone to function. It regulates body temperature, mood, weight, and energy. Literally, your life depends on your thyroid.
Unfortunately a typical scenario is to go for medical advice and help with your list of symptoms, and all that is normally measured is the TSH (thyroid stimulating hormone).
Unfortunately, it is only slightly more useful than saying there is weather outside. If it is far too high or low, that gets attention. But when it is “normal-ish,” symptoms are dismissed. Before thyroid testing, doctors used to treat based on symptoms. That never happens now.
Simply put, the problem is that TSH is only a signaler (from your pituitary) to your thyroid to make the hormone T4. But T4 can’t be used well as is, so it must be converted to the useable T3. This is energy, weight normalization, better sleep, no anxiety or depression, lower cholesterol, warmer hands and feet, and much more. (Click here to go the Thyroid Assessment and see how yours is doing.)
Then, even assuming your thyroid makes enough of the hormone along this pathway, even that might not matter either, because what matters is how much gets INTO your cells’ thyroid receptors.
Certain substances can block this (some vegetables such as broccoli, soy, and the chemical fluoride, for example). And you might be hypothyroid even though your TSH, Free T4, and Free T3 tests are all “normal.”
You can see in the diagram that T4 is converted into T3, but it can go one of two ways. It does some of both, but conditions, such as unrelenting stress, can activate Reverse T3. Think of it as anti-T3. Your Free T3 gets blocked from entering cells, much as a hand over a drinking glass no longer permits refills. When this happens, if Reverse T3 is not tested, all the other numbers might be quite normal looking but you feel terrible!
And to complicate matters even more, the body’s immune system might go wacky and start attacking and trying to destroy your thyroid. This is called either Hashimoto’s thyroiditis (often with high TSH or too little T3 thyroid hormone) or Grave’s disease (the TSH is dangerously low or too much T3). Either is significant and can be tested for via two blood tests, anti-TPO and anti-thyroglobulin. So the complete thyroid panel is TSH, Free T4, Free T4, Reverse T3, Anti-TPO and Anti-thyroglobulin. With all this information you and your doctor can plan out what your next steps should be on your path to feeling better.
In the chart, there are some very significant side-effects of hypothyroidism. Especially for women, the risk of heart attacks rises, and particularly for post-menopausal women.