Re: Misdiagnosed with Hypothyroidism?
I'm as distrustful of MDs as anyone can be. It's always a good idea in my book to double-check what they tell me.
I know nothing about the management of RA and next to nothing about how to taper a prednisone dose; but I do know about hypothyroidism, and I can assure you that this doctor does, too. You are hypothyroid. I have no doubt at least some of your symptoms are due to it, and that replacement of your missing thyroid hormone will benefit you.
Healthy people have TSH around 1 to 1.5 and free T4/3 levels at 50-70% of their ranges. Your TSH is below range, on the hypERthyroid end, while your T4/3 are on the lower ends on the hypOthyroid side. In the textbook world, TSH is supposed to rise once T4/3 become deficient, but in reality it hardly ever works that way. Most of the time, hypoT is caused by auto-antibodies that suppress thyroid hormone production. These antibodies are known to also prevent the rise of TSH, but doctors aren't taught that. It means most people suffer for years in the hypothyroid state before their TSH rises high enough to be diagnosed.
Occasionally, hypoT happens due to pituitary dysfunction. The pituitary produces TSH, a signal hormone that tells the thyroid gland to adjust its output of thyroid hormone. Your below-range TSH coupled with low T hormones suggest that your pituitary might be sluggish. It isn't producing enough TSH to signal your thyroid gland to make more hormone.
A smart thyroid MD would see that your thyroid hormones (T4 and T3) are too low, regardless of your low TSH. Again... In an ideal, textbook world, your TSH would be high with Ts as low as yours. But in the real world, hypothyroidism comes in all shades of gray. Pituitary dysfunction is considered an ususual cause for hypoT, and it's one not commonly recognized. Therefore, an MD who's looking solely for the textbook high TSH/low T4/3 scenario is going to tell you everything is well when it actually isn't. Your trusted MD is mistakenly seeing it this way.
Whatever faults the diagnosing MD may have, he does seem to have better-than-average thyroid diagnosing skills.
Get other opinions if you must. I won't tell you not to trust your first doc, but I will tell you the second is not wrong (about your hypoT, anyway).
"We can complain because rose bushes have thorns, or rejoice because thorn bushes have roses." Abraham Lincoln