Central/secondary hypothyroidism are the same thing.
The problem with your labs is that we don't have reference ranges and those do vary from lab to lab, so I'm just guessing when I say your FT4 "looks" low in the range, because I'm going by ranges we, typically, see but we can't really do that. We have to compare with the range your lab uses.
Good that you've contacted another doctor. As long as you're at it, have them check parathyroids as well. There's no relation between parathyroids and thyroid, other than location in the body, but symptoms can be similar. Check out www.parathyroid.com.
Hypothyroidism is hypothyroidism, regardless of the cause and the symptoms will be the same because your thyroid isn't producing the hormones your body needs.
You have been SO helpful. Thank you so much!
I have already contacted another doctor's office that specializes in thyroid hormones and disorders, so hopefully they will be able to figure me out. I do see what you mean though... after just a little research, I see that my TSH level is low compared to what most labs consider 'normal' and my T4 is on the low end of normal also. Those two things combined look they they point to 'secondary hypothyroidism' so it could be caused by a pituitary problem. The symptoms sure look a lot like mine.
We have to be able to compare your results with the reference ranges used by the lab that did that analysis. You can call the lab or the doctor's office and get them.
The antibody tests you had are negative for Hashimoto's, so technically, that would be ruled out; however, we've had some people diagnosed without antibodies on the basis of an ultrasound. I'd say that's not your case, since your FT4 seems relatively low in the range and as such, we'd expect your TSH to be higher than it is.
An ultrasound would tell whether or not you have nodules on your thyroid. It would also tell if there were swelling/inflammation.
TSH is a pituitary hormone whose sole purpose is to stimulate your thyroid to produce thyroid hormones... Your TSH is quite low, which indicates that it's not telling your thyroid to produce much thyroid hormone. Central hypothyroidism is caused by a pituitary issue, as opposed to a thyroid failure. When the thyroid fails, as with Hashimoto's, TSH keeps going higher as thyroid hormone levels go lower, as the pituitary cranks out TSH in an effort to get the thyroid to produce hormones.
Yes, I think you should find a different doctor and get more tests done. Next time, make sure you get Free T3, with the Free T4 and TSH. It would be good to repeat the 2 antibody tests, in case you do have Hashimoto's and the antibodies just haven't ramped up yet.
When I say "flip flopping", I do mean swinging from hyper to hypo and you're right, early stages of Hashimoto's are often characterized by that type of swings, but other things can cause that, as well, and that may not be what's happening. The sweating, which is, typically, a hyper symptom could be caused by something else.
Again, though, if you have Hashimoto's, we'd expect your TSH is be higher than it is, which is why I'm leaning toward the central hypothyroidism. Regardless of the cause of being hypo, though - it needs to be treated and treatment won't change, but if you have central hypothyroidism, there could be other hormone levels that are off, as well, which could contribute to the way you feel.
My lab results didn't even include reference ranges... they were posted online and beside each one it just says 'normal.'
I told the doctor when we met the day that they drew blood that I just feel like I am falling apart... I know I'm not imagining all of this. I feel terrible. I weigh roughly 55 pounds more than I did at this time last year with NO change in diet. I have no idea what to do next... make an appointment with a new practice/doctor and have them re-check? My current endocrinologist even mentioned that 'if anything your levels are a little low.' I was just thinking "Ok... so should we not treat them then?" I'm so tired of feeling so tired and crappy! I haven't had an ultrasound... what would that do? Something the blood work doesn't?
And what exactly do you mean by central hypothyroidism? I've wondered if maybe I have Hashimoto's... I think I read something about 'flip flopping' being part of that. Like you swing between hyper and hypo?
Unfortunately, your doctor ordered Total T3, which isn't as useful at Free T3
Have you had a thyroid ultrasound? It might be helpful to know if you have nodules.
Your symptoms sound like a mixture of hyper and hypo... like you might be flip flopping and while your FT4 is quite low, so is your TSH, possibly indicating central hypothyroidism.