# Possible to have low FT3 with Graves'?



## Prudence (Oct 30, 2012)

So I have a query:

When I was actively hyperactive, I had FT3 done three times, but all of them resulted in a low level-in a range of my lab of 2.4 - 4.2 pg/mL, it rang up 3.1 two of these times, and a 2.7 one other-yet I actively had Graves' disease, because the uptakes and scans I had proved this. However, those numbers are on the low side (to be fair, the 2.7 rang up when I was taking methimazole, but the other times were with no medication, and I was feeling quite hyper.)

So, what gives? You would think I'd of been higher being hyperactive, correct? I'm just curious if this has happened to anyone else.


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## Andros (Aug 26, 2009)

Prudence said:


> So I have a query:
> 
> When I was actively hyperactive, I had FT3 done three times, but all of them resulted in a low level-in a range of my lab of 2.4 - 4.2 pg/mL, it rang up 3.1 two of these times, and a 2.7 one other-yet I actively had Graves' disease, because the uptakes and scans I had proved this. However, those numbers are on the low side (to be fair, the 2.7 rang up when I was taking methimazole, but the other times were with no medication, and I was feeling quite hyper.)
> 
> So, what gives? You would think I'd of been higher being hyperactive, correct? I'm just curious if this has happened to anyone else.





Prudence said:


> So I have a query:
> 
> When I was actively hyperactive, I had FT3 done three times, but all of them resulted in a low level-in a range of my lab of 2.4 - 4.2 pg/mL, it rang up 3.1 two of these times, and a 2.7 one other-yet I actively had Graves' disease, because the uptakes and scans I had proved this. However, those numbers are on the low side (to be fair, the 2.7 rang up when I was taking methimazole, but the other times were with no medication, and I was feeling quite hyper.)
> 
> So, what gives? You would think I'd of been higher being hyperactive, correct? I'm just curious if this has happened to anyone else.


One reason could be that even when resting, your body is in high gear quickly using up your energy source which happens to be FT3. Another possibility would be antibodies.

Blocking TRAbs (also known as Thyrotropin Binding Inhibitory Immunoglobulins (TBII)) competitively block the activity of TSH on the receptor. This can cause hypothyroidism by reducing the thyrotropic effects of TSH. They are found in Hashimoto's thyroiditis and Graves' disease and may be cause of fluctuation of thyroid function in the latter. During treatment of Graves' disease they may also become the predominant antibody, which can cause hypothyroidism.

Low FT3 is leaning towards hypothyroid; I do wonder what the FREE T4 was for all 3 tests.

Have you had this test? There are blocking, binding and stimulating antibodies.

What about TSI; have you had this test?

TSI
Normally, there is no TSI in the blood. If TSI is found in the blood, this indicates that the thyroid stimulating immunoglobulin is the cause of the of a person's hyperthyroidism.
http://labtestsonline.org/understanding/analytes/thyroid-antibodies/tab/test

Trab
http://www.ncbi.nlm.nih.gov/pubmed/17684583


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## Prudence (Oct 30, 2012)

TSI was "borderline", but it was in the high nineties(I believe 98%) with a range of 0-129% back in 2010. I got it done again this year and it was at a 54%. My Free T4 was actually pretty normal or just right during those tests-with a lab range of .9-1.8, they rang up as:1.4, 1.2, and 1.4 again. The times the FT3 rang up as 3.1 was when the FT4 was 1.4, and the 2.7 FT3 was for the 1.2 FT4. However, when I had the uptake and scans, my thyroid showed I was overactive (very high uptake results the first time before I had RAI-74% , and then 48% for my second one done this past February) and I have no indications of Hashi's from other tests/the scans were indicative of Graves', so it's just...puzzling to me. My FT4 would often be right on the high end of "normal"-1.8 a lot, but occasionally would be fine, as you can see in those. Right now, my second RAI worked and I've been left hypo, and still trying to figure out a dose plan that would be good for me. They've only been running TT3 now, which is at the bottom of the range, but during those times of the hyperthyroid/keeping track of it, the TT3 was in the low 100's (range 60-180, would often pop up around 110-120), yet I felt hyper until I got the TT3's into the mid 80's and 90's. It's a bit baffling, but I just wonder if pesky antibodies were keeping it low?


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## Andros (Aug 26, 2009)

Prudence said:


> TSI was "borderline", but it was in the high nineties(I believe 98%) with a range of 0-129% back in 2010. I got it done again this year and it was at a 54%. My Free T4 was actually pretty normal or just right during those tests-with a lab range of .9-1.8, they rang up as:1.4, 1.2, and 1.4 again. The times the FT3 rang up as 3.1 was when the FT4 was 1.4, and the 2.7 FT3 was for the 1.2 FT4. However, when I had the uptake and scans, my thyroid showed I was overactive (very high uptake results the first time before I had RAI-74% , and then 48% for my second one done this past February) and I have no indications of Hashi's from other tests/the scans were indicative of Graves', so it's just...puzzling to me. My FT4 would often be right on the high end of "normal"-1.8 a lot, but occasionally would be fine, as you can see in those. Right now, my second RAI worked and I've been left hypo, and still trying to figure out a dose plan that would be good for me. They've only been running TT3 now, which is at the bottom of the range, but during those times of the hyperthyroid/keeping track of it, the TT3 was in the low 100's (range 60-180, would often pop up around 110-120), yet I felt hyper until I got the TT3's into the mid 80's and 90's. It's a bit baffling, but I just wonder if pesky antibodies were keeping it low?


Antibodies can really wreak havoc w/ the numbers. It would be to your benefit if the doctor would run your FREE T3 for titration purposes instead of the Total 3.

Here is information.

Understanding the Thyroid: Why You Should Check Your Free T3
http://breakingmuscle.com/health-medicine/understanding-thyroid-why-you-should-check-your-free-t3

Dr. Mercola (FREES)
http://www.mercola.com/article/hypothyroid/diagnosis_comp.htm


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