Normal Free T4, normal T3 yet highTSH. Why?

[ando35]

My labs are as follows:
TSH 9.14 with a range of 0.45-4.70
Free T4 1.4  with a range of 0.71-1.85
T3 1.12  with a range of 0.79-1.49

So why is my TSH high if T3 and T4 are normal?

By the way, to avoid confusion, the T3 is labeled as TRIIODOTHYRONINE (T3) 1.12 ng/mL range: (0.79-1.49). I think this is total but not sure.

[gimel]

Even more important than thyroid hormone levels, what symptoms, if any, do you have?

[ando35]

I have gained a ton of weight. Part of it was eating but then I stopped eating a lot and the weight didn't come off like it normally does. I was taking aleve every day for a month with my synthroid and I think that might have affected me because aleve's main inactive ingredient is magnesium.

[flyingfool]

The "rule of thumb" to feel well is to have BOTH of the following:

1) Free T4 to be 50% of the range or slightly higher.

AND

2) Free T3 to be 50% to 67% of the range with many people needing more towards the 67% of the range.

with that in mind:

Your FT4 is at 60% of the range. The rule of thumb is 50% or slightly higher.

Your FT4 is only 47% of the range. Which is close to but below the bottom of the "rule of thumb".  So if you are suffering from Hypo symptoms, you have a lot of way to go to get towards the 67% of the range.

In summary;  Your FT4 is HIGHER than the rule of thumb, while your FT3 is LOWER than the rule of thumb.  Which further indicates that you may have issues with conversion of T4 to T3.

That would suggest that leaving your T4 medication alone and adding in a source of T3 medication such as Cytomel.

So I would recommend that you discuss with your Dr that instead of raising your T4, to instead add a starter dose of Cytomel.

But that is just my thoughts and  recommendation.

[ando35]

Great info, thanks!

[gimel]

Have you been tested for Vitamin D, B12 and ferritin?  Hypo patients are frequently too low in the range for those.

[des900]

This is subclinical hypothyroidism and in this T4 and T3 is maintained and TSH is elevated. In this condition the best approach is to rule out common deficiencies like Vitamin D, B12 and Ferritin and supplement if its not optimal. After making those in optimal range repeat the thyroid function tests again like TSH, Free T4, Free T3 and Anti-TPO Ab and based on the values need to take suitable thyroid hormone pill at some dosage especially if experiencing hypothyroid symptoms like fatigue and poor reflex, mental sluggishness etc.

[ando35]

Yeah, I have been on synthroif for two years. I Tkae 75 MCG and they just upped me to 88.

[des900]

OK the above result on 75 mcg synthroid. Also rule out the deficiencies especially Vitamin D. The blood test name is 25-hydroxy Vitamin D.