I am just interested to know about Basal Body Temperature for determining low function of your thyroid. Other symptoms Lack of concentration, feels cold when outside temp is very warm, eczema, short temp memory loss, always fatigue. From a blood test TSH 2.6 and just recently TSH of 3.2, from what I am reading the normal ranges of TSH is very broad. Here in Australian the upper limit is 4.0, but I have read, that the range should be tightened to upper limit of 2.5 Can I have some comments?