TSH levels on replacement therapy

[Babs16]

Hi,

I was diagnosed with Hashimoto's thyroiditis almost a year ago at age 45 and have been on Synthroid 0.05mg since Nov 2006.

My TSH level was around 2.4 prior to going on Synthroid but I was told I should be on it to see if it prevented further progression of my vitiligo (which was the reason I was checked for Hashimoto's in the first place).

After 3 mos of medication my TSH level was around 1.0.  The progression of vitiligo has stabilized and I have been feeling much better-- less anxious and irritiable (even though I didn't realized how bad I had been feeling until after I'd been on the medication for a while).  My GP told me she wanted to keep my TSH level around 1.0

I just had a retest of my TSH level and it has come back at 2.98.   My GP is not concerned with this new level and did not order a medication change or retest.

My questions:

Is it normal for a TSH level to rise while on an adequate dose of replacement medication?   How sensitive is a TSH level and/or what are normal fluctuations?

Should I be followed by an endocrinologist?  I asked my GP and she didn't feel it was necessary.  I should I also mention that I have tested positive in the past for anticardiolipin antibodies (during my third pregnancy 11 yrs ago) coupled with thrombocytopenia.  I have never had a thrombolic event and my most recent platelet count was slightly below normal (139).

Thank you

[sarann]

I put the incorrect dose of Levothyroxine in my question...  It is actually 125mcg and 100mcg.  Sorry..

[sarann]

My TSH level was  0.151, I was on 0.125mcg of Levothyroxine and my Dr. changed my dose to 0.100mcg Levothyroxine, If the ideal TSH is 1.0 for conception then am I still too low and is there something else I should be doing?

[Mark Lupo, M.D.]

TSH may rise as the hashimoto's progresses - 0.05mg is a relatively low dose.  Target TSH is around 1.0 -- normal fluctuation may be up/down 0.5 points.