My doctor has been saying for a few years that my thyroid is enlarged, however, no tests have been done on it so far. She was just going on visual exam. All TSH tests through 2007 were normal. My last one, in 2007 was 2.something.
Last week, they ran another TSH and Free T4. TSH was 11.6 (range 0.27-4.20) and Free T4 was 1.11 (unsure of the range, but it was "normal."). Since I had been having symptoms, including low heart rate (58) with heart palpitations and a lot of fatigue, they decided to start me on 25 mcg Synthroid.
To make sure the TSH wasn't an error, they ran another one (before starting Synthroid). TSH was 12.82. No repeat Free T4 was done. Thyroid antibodies were negative: TPO was 3.8 (range <9.0) and Antithyroglobulin was 3.9 (range <4.0).
My questions is, since Hashimoto's is the most common cause of Hypothyroidism, I suspected my antibodies would be elevated. All the other causes I've found associated with Hypo (thyroidectomy, radiation therapy, thyroid surgery and medications) don't apply to me at all. What could be causing an elevated TSH with all other thyroid labs normal?
I have a thyroid ultrasound scheduled for next week, but that's it. I'm waiting on a referral to an endo, but it's going to take 6 weeks or so to get in to the office.