TSH and antibodies

[NYCMARY]

I have been seeing a doctor for the last three years to keep a check on nodules.  During this time my TSH has been what he called normal (greater then 3.0 but less then 4.0).  I have been gaining weight and have pain in the nodule area, my TSH check was 3.7.  The doctor told me my problems are not related to the tyroid so still felling awful and in pain I went to another doctor.  My new doctor ran new blood tests, I just received a call that everything was normal so far.  The odd thing is that three weeks ago the TSH was 3.7, today it is 1.4.  Test done at different labs, why would there be such a big difference?  New doctor said he is still waiting for antibody test results which could explain problem.  I'm confused because last four tests should a TSH rising (3.0, 3.4, 3.7 ...)and last tests is 1.4. What is an antibody test and how can it explain the difference in the TSH? New doctor also ran blood work to look for thyroiditis, it too came back normal. He advised me to take advil until antibody test is in?

[NYCMARY]

Thanks, wondering if anyone else has had this happen.  TSH reading 3.7 and three weeks later 1.4.  No meds taken.

[Mark Lupo, M.D.]

Not sure why the difference in the TSH -- the antibodies will tell if the immune system is causing inflammation in the thyroid (Hashimotos).  I think a thyroid ultrasound would be helpful in addition to the antibodies.