Thyroid panel without T3

I went in to urgent care last week with vertigo and history of hyperthyroidism.  Per my request, the doctor ordered a thyroid panel, but the results don't include free or total T3.  What would be the reason for ordering a TSH and a free T4, but not a T3?  Isn't T3 the active form?  My TSH was .02 and my T4 was 1.8.  I was highly unimpressed with this doctor in general.  She was the first doctor who I've ever felt was truly incompetent.  Is there a good reason to omit a free T3?  Thanks!

[AR-10]

If it was urgent care, they can hve TSH and Free T4 results in a half hour.

T3 tests are often sent out, and take three or four days to get the results.

At least that's how it works at my hospital, in the ER.

T3 tests are not run nearly as often as Free T4, because of expense, time, and the fact that 90% of the time, it is redundant. The Free T4 and the Free T3 test results SHOULD mirror each other, and usually do.

[Call_me_MN]

So getting TSH and Free T4 is sufficient to determine if you're on the right dosage of Synthroid/generic and that all is well? I posted a similar question a few weeks back and got no response, so I've been wondering about this too.

[AR-10]

TSH and Free T4 are tests that my hospital can run in about a half hour.

They have to send the T3 tests out to a lab out of state.

Unless you have an unusual problem, your Free T4 and your Free T3 tests will look very similar as far as how much free hormones you have circulating.

My Endo, tied to a much larger hospital, rarely wants to see my T3 results. She has me get a TSH and a Free T4, and bases all her decisions on those results. My GP, who knows as much as she does, I believe, does the same thing.

I had my Free T3 checked maybe twice last year, and once this year, because I specifically asked for it, and she humored me.

I've Had my TSH and Free T4 checked at least six times this year so far. Maybe more than that. Looking at the T3 each time is redundant. Now, if I get to the point where I'm only getting checked twice a year, then I might insist on a Free T3 at least once a year.

I think it's good to look at your T3 once in a while, because there are things that can go wrong, but it is unusual for the T3 and T4 to not be at nearly the same level when you look at the results within the lab limits.

A small percentage of people have trouble converting synthetic T4 (such as Synthroid) to T3, and need to take Armour, or Synthroid and Cytomel. That is where the Free T3 test shines, as it will show a high T4 and a low T3, indicating a problem.

If your TSH is rising, and your Free T4 looks good, then a Free T3 test may show wherein the problem lies.

But for most of us getting routine checks, A TSH and Free T4 is all the doctor needs.