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Thyroid Problems/low TSH normal free T3, T4


Dear Dr. Kulkarni,
My lab results for years have shown an undetectable level of TSH, but mid range FT3 and  FT4. My former Dr, who passed away, said it was simply because I was taking T3 as a supplement for hypothyroidism , along with the T4( synthroid) and that naturally stopped the production of tsh, which makes perfect sense to me being a biologist. I felt awful on the T4 alone, but fine on the T4/T3 combo.
I have no symptoms of being hyperthyroid-my temp rarely reaches 97.0 degrees, and I'm usually cold. My HR isn't high and I'm not getting palpitations, or diarrhea. new Dr will not believe I am not hyperthyroid, solely because my TSH is so low, so... says I need to stop the T3 and take only the T4.
Please... what is your opinion? I have tried this several  times, and each time, sure my TSH goes up, but I feel awful and it takes months to feel good again and involves finding another DR who is willing to believe that for some reason T4 alone does NOT help me. Now I'm back at square 1 again!
Any help/advice/comments would be very much appreciated-thank-you so much for your time.

Hello Tina,
Warm welcome to you!
Yes if you are taking high dose of T3 and T4 they can make TSH undetectable. Being on T3 and T4 both works better in some patients but it should not push you towards hyperthyroidism. Medically speaking your doctor should try to keep TSH in range. If its undetectable for long duration, it could cause serious problems like hypertension, heart problems later. So advisable to bring TSH under control. My suggestion is dont stop medications, but you can reduce T3 and T4 dosages gradually till your body gets adjusted to an appropriate dose. Please send your thyroid reports if you have. Also send what medicines you are taking.

Thanking you!

Thyroid Problems

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Dr.Shrinidhi Kulkarni


Dont hesitate to ask your health related queries. 24 X 7 ready to provide solutions to your health concerns. All questions are welcome ! Speciallly Endocrinology.


Working as a Doctor in Primary Health care Centre.

KIMS, Bangalore

MBBS, Intership in Internal Medicine

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