You must be feeling absolutely terrible. Sounds like hypopituitarism to me. You should get this checked out by osteopath (if in US) or endo asap. Demand test for AM Cortisol (no latter than 8am), AM ACTH, TSH, fT3, fT4, estrodiol, testosterone, LH, FSH and IGI-1
Also see: http://www.realthyroidhelp.com/ for the hypopit forum.
It may be a transitory thing, and clear up. But if you are below lab limits that is not a good place to be.
Your T's need to be in the upper normal limits. The meds are a good thing. They are feeding your whole body right now. You will need fairly frequent blood tests, though, for several reasons.
The low TSH thing is what your Endo is going to have to figure out. There are several things that could cause that, and drugs you are taking or severe illness could once again be the root cause.
Your pituitary is not sending TSH when it should be. that could be a pituitary problem. Or it could be a problem with the hypothalimus. Or it could be a problem with the signals not getting from the individual cells to the hypothalimus.
If everything starts clicking again and your TSH comes back up, then you will need to put a brake on the meds quick. The root cause is probably your medical hstory, but predicting an outcome is tough.
You need to have more tests run.
Thank you for your response. My T3, T4 and TSH are all below the labs normal limits. I am just confused b/c with "usual" hypothyroidism, you usually see a HIGH TSH level and then low T4 and my TSH is also low. My doc does have me on the replacement meds Cytomel and Synthroid. I guess I will probably just have to wait it out and see if this is just temporary (from illness or meds) or a more permanent post-partum hypothyroidism.
First, I understand about half of that stuff, but here's what I think.
It depends on how low your T3/T4 is.
You're in an unuasual situation. It sounds like you TSH has been suppressed, either by meds or illness. The question is, how low is your T3/T4?
If it's below lab limits, then I would think replacement hormones would be a good thing, but your levels would need to be watched very closely. Sooner or later your pituitary SHOULD start producing higher levels of TSH, and then your thyroid SHOULD return to normal function.
When your T3/T4 get low enough, you will feel hypothyroid symptoms, regardless of what your TSH level is.