I think that we are sensitive to small variations to what is our correct TSH. The answer is "listening" to what your body is saying. The easiest painless test you can do at home is to take your body temp. in the morning before getting up. Track this morning temp for at least a week on graph paper. Mine was hovering around 95 F. when I finally got tested. Rember this is a total body metabolism hormone so the effects are global (in a body sense) The only argument to the body temp. test is that unless you know what that was before treatment you may be guessing as to what that should be. 98.6 F. is not "normal" it is an average (but 95 was not questioned by my doc he agreed that was low). In my opinion if you weren't feeling cold before and you are now then you should consider Thyroid issues as the possible cause.

In order of most noticed issues for me:
1. cold sensitivity, cold hands and feet
2. cold body temp.
3. constipation (I know it ain't fun to talk about) 4 to 5 days sometimes longer without a BM.
4. shortness of breath (this is because the blood doesn't take up oxygen as well when your metabolism is slowed down.)
5. fatigue which is rather odd feeling. I for example would wake up at the regular time but will have no interest in getting out of bed.
6. dull slowness of thinking, or being "in a daze". This is only when the TSH climbed above 7 (actually when first tested it was 18. I could sit at my desk and stare at anything and wonder why I was just staring for 5, 10, 15 minutes at a time.) My wife believes she can tell when I am "off" by my being quiet. (may be an advantage for her)
6. Hair coarse and nails brittle, eyes feel gritty. These too were when the numbers were high for quite a while.

David, from what we have observed here "real life" it is not correct to assume that thyroid problems always show up early after treatments end. It could happen any time after. Add to that, age related hypothyroidism (which is rather common in the non-cancer population), means this is an important issue which can often be overlooked or brushed off by Docs. In conversations with many doctors in my area (both involved with my care and not) there is a wide range of attitude (read apathy) in regards to this simple-to-fix health problem. If you are lucky you might have a Doc that will really listen and do all the tests. Others are more than happy to have you sit at 5.5 if you don't say that you are feeling "off". I happen to feel 2.5 is my target number and really had to push (complain) to get there.

When my thyroid began to under produce, it was also gradually declining. This meant that getting my numbers to normal took over a year. Because of how I felt during this time (crappy) I am somewhat passionate about people getting on this right away. Don't wait! I have been known to mention getting tested to people while shaking their hand (because their hand was cold). My dad is now on synthroid because I noticed his hands were cold and urged him to get tested.