Low TSH Normal Free T3 and Free T4 Post RAI

[beach45]

Dr. Lupo:

I am around seven months post RAI for treatment of Graves Disease; I went very hypothyroid end of August 2012.  I am on 125 mcg Generic  Levothyroxine for 2 months (started back 9/20/12).  Prior I was on 75 mcg and 100 mcg Synthroid.  I am still feeling some signs of hypothyroidism like not losing weight especially in the middle (despite excellent diet and exercise for a very long time), feeling fatigued mid afternoon on, some confusion and memory issues, hair loss, and achy stiff muscles/joints especially in calves and knees. I am 53 and my menstrual cycles have disappeared also.  I am concerned my endocrinologist will lower my Levothyroxine dosage to 112 mcg and I know, if for instance, my Free T3 goes down due to this, I will really feel horrible as anything lower than a Free T3 of 2.9, I do not feel right. I also feel hypothyroid with TSH of anything over 1.5. My endocrinologist believes for an over 50 TSH should be between 2-3.  Is this all normal post RAI as I thought after this many months I would be feeling better? I read different dosing guidelines for Levothyroxine like this one: 1.7 mcg/kg/day and I am 163 pounds so it seems 125 mcg of Generic Levothyroxine may be right for me?  (In 2-1/2 years with Graves treatments I gained 25 lbs total on both Methimazole and now post RAI):

9/19/12
Free T4  1.08    (range 0.82 - 1.77)
TSH      30.790 (range 0.450 - 4.500)
10/18/12
Free T4  1.87    (range 0.82 - 1.77)
TSH       0.871  (range 0.450 - 4.500)
11/20/12
Free T4  1.72    (range 0.82 - 1.77)
Free T3  2.9      (range 2.0 - 4.4)
TSH       0.289  (range 0.450 - 4.500)

Thank you very much in advance for your medical input.

[beach45]

Thank you Dr. Lupo for your response; unfortunately I am not having an easy time working with my endocrinologist and he is not listening to my symptoms.  He has told me and others numerous times he goes only by lab values; why others have left him.  So I am looking to move on to a physician who will really work with me with both lab values and how I feel.

[Mark Lupo, M.D.]

The TSH range may vary from patient the patient, typically we should for 0.5-2.5 but adjust this based an individual situations.  You need to talk to your endocrinologist regarding specific changes and response to these changes.