I have a low THS (.04) and the dr thought I had hyperthyroidism, but T3 & T4 are ok. What does this all mean?

My mother, all five of her sisters and my grandmother on the other side all have thyroid problems, so I wasn't too shocked when it was discovered that I have a low THS level (ranges between .01 and .04 instead of being between .34 and 5...). My T3 and T4 tests came out good, though. So, what is the THS test, and what does it mean for my health condition and treatment? I originally went in because of lower-back pain, but I assume this is unrelated.
Answer:
There are two different types of tests for T3 and T4. One checks the levels of free T3 and T4, meaning the amount in your bloodstream. The other checks the levels of T3 and T4 that are bound, meaning the amount that is unavailable. If the overall THS is low, but the amounts of free T3 and T4 are normal, it means that your body is getting and using a normal amount without being stimulated. It probably will not be treated unless complications or symptoms occur.

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TSH (thyroid stimulating hormone) is a hormone that is release that causes your the release T3 and T4 from your thyroid. In hyperthyroidism people typically have low TSH and high T3 %26 T4. Normally (with not thyroid issues) TSH causes the release of T3/T4 but in your case you are releasing T3/T4 without TSH which is considered overactive thyroid. Now in your case you have normal T3/T4 levels with low TSH which doesn't necessarily suggest hyperthyroidsim (to have hyperthyroidism your T3/T4 levels should be higher) - so you may just have "pre-hyperthyroidism" - this may just indicate that you may develop a thyroid problem(like the rest of your family) which can be treated with medication.

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On the contrary, my TSH is normal (1.9) but my T3 and FT4 are high so I'm experiencing hyperthyroid symptoms. To further confuse the issue, I am actually taking medication for hypothyroid (because at one time my TSH was 161). So I'd venture to say that if you're not experiencing symptoms of hyperthyroidism and your T3 and FT4 are good, you're okay for now. You're smart to watch it though and always consult with a doctor. Problems with your thyroid effect almost every function of your body...especially with a family history - keep watch!

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