I have taken synthyroid for years.
I was diagnosed with Hashimoto's back in May.
I recently saw my endocrinologist and had follow up labs done.
My TSH was 2.46 with the range being .5-6.40
My T4 was 1.20 with the range being .53 -1.80
She is retesting in three months.
My questions are:
does the T4 levels show how well the synthyroid is being utilized/ converted ?
being on the higher end does that mean that my body is not using the synthyroid as well as it could?
When she starts trying to explain this stuff to me I get a bit confused , please help me understand
Since Synthroid provides only the T4 thyroid hormone, you won't know how well that supplemental thyroid is being utilized/converted until you get a free T3 test. The body (cells) actually utilize T3. T4 must lose a molecule to become T3 before the cells can utilize the synthetic thyroid supplement. You can have a normal (midrange) T4 result (which you do), but still have hypothyroid symptoms if your body doesn't easily convert T4 to T3. A normal T4 result with a low T3 result may indicate you don't easily convert T4 to T3. Also a reverse T3 test can show how well your body converts T4 to T3. Normally T4 is converted to 60% reverse T3 and 40% free T3. If the reverse T3 test is very high, you may not be converting T4 to enough T3. However other illnesses can also cause high reverse T3 results.
I wanted to repeat that your T4 score was midrange normal, not the high end. Also a good indication that your synthroid is being utilized is your lack of hypothyroid symptoms. What were your presenting hypothyroid symptoms (fatigue, weight gain, feeling cold all the time, hair loss, etc.)??? Have those symptoms decreased?
Finally, did your doc test your Hashimoto's antibodies (TPOab test) when you had your recent labs?