Central Hypothyroid? TSHr Antibodies? Does it really Matter

[schmede]

I have been having hypothyroid symptoms.  Hashimotos runs in my family and I recently had the following test results:

TSH=1.4967 (reference range 0.35-4.94)
FT3= 2.82 pg/ml (reference range 2.3-4.2)
FT4= 0.9 (reference range 0.7-1.48)
TPO=3.10 (reference range 0-9)
RT3= 235 pg/ml  (reference range 90-350)

My TgAB was also negative.

My doctor feels I either have Central Hypothyroid or that I may have TSH blocking antibodies.  I chose not to do further testing because I felt the treatment options were the same.  Was this a mistake.  Would it have been important to do an pituitary MRI scan or test those other antibodies?  

I seem to be responding to treatment with NDT

[schmede]

My doctor feels that given my symptoms and family history, it is a problem that my FT3 and FT4 are in the bottom of my reference ranges.  After consulting with a endocrine specialist at a research University they both felt it was the right course of action for me to do a trial of thyroid treatment.

Is it strange that I am responding to the treatment?  And my response in many ways is physically measurable such as improved menstrual cycles and weight loss (from 119 to 114 within two weeks)?  

What other testing would you recommend?  If thyroid issues are not my problem. I would very much like to get to the bottom of why I have felt so crushingly exhausted this year.

[Mark Lupo, M.D.]

You have completely normal thyroid testing - would look at other causes for your symptoms.  Remeber that "hypothyroid symptoms" are very non-specific and in most cases actually are not caused by a thyroid problem.