TSH extremely low

[nancygif]

Hi, I have been treated for  Hashi's for just over 3 years.  
I take synthroid and cytomel.  Everything was good until this past Feb when after blood work my doctor said my TSH was too low and he dropped my synthroid.   Each time blood work done (early May, late June and late August -TSH .12) my TSH remained low and my synthroid was cut each time.  Doctor said free T4 and T3 fine each time.    
Got latest labs back last week in the mail (a first) and my TSH is <.004 with Free T4 of .64 (.61 - 1.76).   T3 not done.  I am taking half the dose of synthroid now (1/2 of a .125 tab a day) than I was back in January (.125 a day).  My cytomel dose through all of this was 15 mcg in morning and 25 mcg at 3pm.  
My hypo symptoms have returned and the biggest bummer is I have gained 9 lbs in the past 8 months after losing 20 lbs 3 years ago and keeping it off.
Another tidbit is I am 51 and had my first bout of hot flashes a month ago.  They were many times a day for 7 days straight but haven't had any since.  My period is crazy but don't know if its thyroid or peri-menopause.    
I've been researching all of this online and am wondering if I could have adrenal fatigue, pituitary problem and/or estrogen dominance.  
I am expecting my doctor (gp) to call as soon as he gets the results.  I did email him and tell him about the weight gain and the return of hypo symptoms but have not heard from him yet.
What should I pose to him as a next step in figuring this out.  Is there a medical website he could go to for more info on hypothyroidism that he would trust?  Would a total change in meds (armour) help?  What tests should be done?
Thanks for your help.
Nancy

[Mark Lupo, M.D.]

The amount of cytomel is fairly high (total of 40mcg/day -- roughly the equivalent of 160mcg of synthroid, which in addition to the 125mcg 1/2 tab is 222.5mcg of T4/day -- more than what most people need).  Going through menopause may be more of the problem than a thyroid imbalance but change in estrogen status may alter thyroid requirements.  Would consider consultation with an endocrinologist to sort out the best options.

[curisa]

My TSH has also been extremely low since starting Cytomel.  My T3 and T4 are fine, and have been for years.  Actually it started when I switched from Synthroid to Armour Thyroid, then to Thyrolar.  I feel too much of a difference with the additional T3 and do not want to go back to only taking Synthroid.  I tried cutting back the Synthroid as recommended by the endocrinologist I was seeing.  She refused to believe that it was the Cytomel, and just kept insisting I was hyperthyroid.  My T3 and T4 continued to drop, but she said that "only the TSH counts"!  When I was back to sleeping 14 hours at night and still falling asleep at my desk, I quit seeing her and went back to my regularly scheduled dosage of Levothyroxin and Cytomel.

So now I wonder, if it is the additional T3 that causes the TSH to "go missing" and what it really means?