How important is Reverse T3 test?

[zepo]

I am about to have a full thyroid check (suspected hypo). The private doc I spoke to yesterday didn't advise checking Reverse T3. Is he right to say that? Should I do the other tests first and only if they are abnormal, then do the RT3? I don't want to spend unnecessarily. Thanks.

[SeasideSusie Remembering]

Zepo

Don't bother with the expense of an rT3 test. Reverse T3 generally has two causes - one being a very high FT4 which tends to happen when taking Levo and it's not converting to T3 properly. If you suspect you are Hypo then you wont have a high FT4 naturally anyway. It can also be caused by illness, infection, etc. It's very unlikely that rT3 is going to be a problem and if it is high the rT3 test can't tell you why it's high.

[zepo in reply to SeasideSusie]

SeasideS

Thanks. So he is right then - well that's a good start. That'll save me £94 then.

[greygoose in reply to zepo]

I second that. rT3 is one of those tests that will tell you if something is wrong, but won't tell you what it is. Like TSH, CRP, ANA. You then have to do more tests to find out the problem. If you just did those tests in the first place - like FT4/3, antibodies, ferritin, etc. - you'd save yourself a lot of money.