Thyroid Disorders Community
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8256587 tn?1399897506

thyroid function test

Hi these are my thyroid function tests done last month.

(private blood test)

TSH - 5.01 (0.2-4.2)
FT4 - 18.7 (12-22)
FT3 - 5.2 (3.1-6.8)

(registered doctor)

TSH - 4.5 (0.2-4.2)
FT4 - 19.3 (10-22)

I have gained an extra 7 kilogram of weight and my doctor has now increased my medication to 125mcg from 100mcg but will not let me see my Vitamin D results even though they are normal. I don't understand why my doctor has increased my medication when I am getting a blood test done for thyroid next week, this is so confusing. I don't know whether to stick to my current dose or increase it as he has told me to?

Thanks :)
5 Responses
649848 tn?1534633700
Your FT3 and FT4 levels are upside down.  FT3 levels should be higher in their range than FT4 levels in theirs.  Yours are opposite with FT3 levels at 56% of the range and FT4 levels at 67% and 77.5% respectively.

It looks like you could stand to decrease the T4 medication and add in a bit of T3 medication in order to bring your FT3 level up and decrease the FT4 level.  

It would appear that your doctor increased your medication in response to your weight gain, but increasing FT3 level would do more good.  Is there any way you can get him to add a T3 medication?
8256587 tn?1399897506
Thanks for your reply.

When I spoke to my doctor on Friday he is only interested in increasing my T4 medication. He didn't know about the weight gain, sorry. I didn't tell him, but I thought it would be a good thing since I was underweight to start with.

I did ask my endo if she could look at my FT3 levels but I have heard nothing back about this. I don't know if they have the blood sample tested or if I have another date to have my FT3 levels checked. But since she is interested in my FT3 anyway would she think about adding in some T3? I thought my labs for FT3 look good but do they not? I thought "in range" was good.
649848 tn?1534633700
"I don't know if they have the blood sample tested or if I have another date to have my FT3 levels checked."  I don't understand what you mean by that. You have an FT3 result; won't she just look at that?  I don't know your endo, so I have no idea if she'd be interested in adding T3 med or not.

Your FT3 results don't look "horrible"; in fact, if your FT4 result wasn't so high, your FT3 might actually be okay at 56% of the range, since rule of thumb is upper half to upper third of the range and you're in the upper half.

How long ago were the labs posted above taken?
8256587 tn?1399897506
Thanks for your reply.

When I spoke to the endo at my appointment she asked me if the private blood test result for the FT3 was based on the same assay. I was told by the private lab company that the endo labs use the same assay as the private lab.
The endo did suggest she test my FT3 again if needs be and that she would let me know about this but I received no phone call or letter about this. So I assumed she had used the sample the doctor lab still had as the doctor lab did the blood draw the same time as the private lab blood draw was done.

I received an email from the endo yesterday saying the following about the FT3 test:

"The FT3 is converted from thyroxine taken orally by enzymes within the body hence the increase in levels in May. Although the reference ranges are the same for local and private tests, I’m not sure if the assays are the same. Our labs are under constant recalibration to reduce errors but I’m not sure of standards for the private lab."

The labs posted above were taken on the same day which was the 21st May 2014.
Avatar universal
Recently I took blood test for TSH, the value 10.53
Free Triiodothyronine (FT3)  2.92 pq/ml
Free Thyroxine   (FT4)      o.92  nq/dl, kindly advise me to prevent HYpothoriod  by taking natural food/veg/fruits/ without medicine.
I am taking Lithium regurlarly.
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649848 tn?1534633700
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1756321 tn?1547095325
Queensland, Australia
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