Blood Testing Results

Is the free thyroxine referring to T3 circulating in your body? It is 1.0 and the range is.9-1.8. If my TSH was 9.06, it seems the pituitary is signaling the body to make more thyroxine. If it is the T3 reading it's in the normal range.
Is it the TPO antibodies that are inflaming the thyroid gland?
I was just wondering why I'd need Synthroid if I am making T3?
It is confusing at best.
Thanks for your help.

[mtkst13]

thyroxine is t4.  triiodothyronine is t3.  80% of what the thyroid makes is t4; 20% is t3.

your free t4 is definitely on the low end, and your pituitary is sensing that you need more t4/t3.

what labs did your doctor run?  once your condition has been diagnosed, a lot of times docs order only tsh and free t4....even though they really should evaluate free t3 as well.

[goolarra]

If your TPOab is elevated. it means you have Hashimoto's thyroiditis (an autoimmune disease), and yes, it is the antibodies that are inflaming the thyroid.

You are still making some T3 and T4.  However, it is most likely not enough since your TSH is elevated also.  Your thyroid can no longer keep up with your body's needs.  Most (not all) people feel better when their FT3 is in the top third of the range.

I agree with mtkst13...you should ask for FT3 also.

Do you have hypo symptoms?

[gimel]

From the range you gave, it looks like the number (1.0) probably relates to total T3.  Although this result is low in the range and seems to fit with your TSH result, it is not the best test for thyroid issues.  As I responded to your prior post, free T3 correlates best with hypo symptoms, with free T4 a distant second,  and TSH has a very poor correlation.  

Regarding your question about free T3,  I think this info from the web site About.com might clear things up a bit.

Triiodothyronine (T3) is a thyroid hormone that circulates in blood almost completely bound (]99.5%) to carrier proteins. The main transport protein is thyroxine-binding globulin (TBG). However, only the free (unbound) portion of triiodothyronine (free T3) is believed to be responsible for the biological action. Furthermore, the concentrations of the carrier proteins are altered in many clinical conditions, such as pregnancy.

In normal thyroid function, as the concentrations of the carrier proteins changes, the total triiodothyronine level also changes, so that the free triiodothyronine concentration remains constant. (In an abnormally functioning thyroid, this is not necessarily so). Measurements of free triiodothyronine (Free T3) concentrations, therefore, correlate more reliably with your clinical status than total triiodothyronine (T3) levels.

[scrutiny]

Thank you for answering.
My first and only visit, I told the endo. that I had a prior blood screening for general health and the TSH came back at 9.06. I thought I had a swelling on the left lobe and he said it was a small goiter. He then ran labs and the report is as follows:
Free Throxine-1.0 (range-.9-1.8) ng/dL-it wasn't flagged
Thyroglobulin Antibody-<20.0 (range-0.0-35.0) iU/mL-negative for Thyroglobulin Antibodies
Thyroid Peroxidase AB-flag-H-168.0 (range-0.0-35.0) IU/mL-Postive for TPO antibodies.
He didn't give a diagnosis, just said I needed thyroid and prescribed 50mcg day.
At the time I saw him, I was exhibiting hypo symptoms, cold, tired, not any severe hair loss, but dry skin, hair, severely dry eyes, not gaining weight, some fluid retention eyelids, fingers, ankles, not severe though.
That is why I wanted to know if the Free Thyroxine of 1.0 was T3 and it is within the range the lab stated and wasn't flagged so I wondered if that is the circulating thyroxine and it is in the normal range, why would I need thyroxine?
I will check out the about.com site for more information. I appreciate your input.

[mtkst13]

you are probably at the beginning stages of hashimotos.  your free values are definitely on the low end, and since your tsh is elevated and you're having symptoms, you need thyroid replacement.  you'll have to be evaluated every 6 weeks until your levels and symptoms stabilize.  then you'll have bi-yearly (at least) appointments to make sure your meds are still at the right level.  if it is hashimotos thyroiditis, you'll need med increases eventually, as hashimotos slowly destroys your thyroid and its ability to produce thyroxine and triiodothyronine.

having the slight fluid retention is consistent with hypothyroidism.  if you don't take the meds, it'll get worst.  you'll start feeling a lot worst.  i would definitely start taking the low dose synthroid.

[goolarra]

I think there's some confusion going on here.  Free thyroxine is free T4 (FT4).  Yes, it's in the range, but very low in the range.  It is not FT3.  Your low FT4 and high TSH indicate hypothyroidism as do your symptoms.

You would need thyroxine so that you would feel better, i.e. your symptoms would go away.

[Smilerdeb]

I agree with Goolarra 100%.