tsh /t3 t4 level

[Debbie_001]

I have had hypothyroidism for 24 years. Just the last year, I have had low TSH readings (.01 to .03) but normal T3  and T4 tests. I have slowly reduced synthroid from my normal .125 to .112  to .1 and now .1 with only .05 on Sundays. What could this mean since T3 and T4 are normal? My dr. said to continue same dosage for 3 mos. and return. If no changes, may have to do brain scan.

[Debbie_001]

thanks for the interesting article. I will absorb it and think about perhaps finding a different endocronologist - it is interesting that you feel my dosage should not have been reduced while he continues with the reduction.

[gimel]

First I'd like to reemphasize that TSH has no direct effect on symptoms.  It is a pituitary hormone that supposedly indicates the levels of the actual thyroid hormones, which are T3 and T4.  It is not a diagnostic, worthy of being used to determine meds levels.  If you had a very low level of TSH and low T3 and T4, and were  not taking meds, then that might be indicative of a pituitary problem.  Since you are on meds, then my personal opinion is that your TSH level likely only reflects your medication and is not indicative of the need for a scan.  
Without knowing what reference ranges are used by your lab, I can only assume they are close to those I am familiar with.  In that case, both your FT4 and T3 results are low in the range, indicative of a continuing hypo problem, and the need for increased, not decreased, medication.  This is consistent with your reports of being tired and forgetful.  

I suggest that you read and absorb this article and perhaps give a copy to your doctor and have a good discussion about your desire to be treated based on symptoms and having your  FT3 and FT4 tested and adjusted with meds as required to alleviate those symptoms.  If the doctor cannot agree and still wants to only go by TSH, then you will need to find a good thyroid doctor.

http://www.hormonerestoration.com/Thyroid.html

[Debbie_001]

thanks for your insight.
My last testing this month - T3 109 and FT4 .8 TSH .03 (which has gone from undetectable within the last year)
the doctor mentioned brain scan because he thought it might be a pituitary problem. My main symptom is fuzziness/forgetfulness. I also feel tired a lot and don't seem to have much ambition. It just seems strange that suddenly my TSH would be so low after all this time

[gimel]

Having a low TSH level doesn't make you hyper unless you have hyper symptoms to go with it.  And hyper symptoms, or hypo symptoms are directly related to the real thyroid hormones, FT3 and FT4.  TSH has no direct effect on symptoms.  In my opinion the best approach to treating a patient is to listen to symptoms and test and adjust FT3 and Ft4 levels with meds as required to alleviate those symptoms.
I have no idea why your doctor would mention a brain scan.  If it was related to having a suppressed TSH, when being medicated enough to try and relieve hypothyroidism, this is not that unusual.  And by the way what were your actual T3 and T4  test results and reference ranges.  Also, was the previous amount of Synthroid enough to relieve your hypo symptoms?  Since reducing the amount, are you having symptoms?

FWIW my TSH level was < .05 for over 25 years, without ever having hyper symptoms, while on 200 mcg of Synthroid.  In fact I still had lingering hypo symptoms because I only recently found out that I had a T4/T3 conversion problem.