L.M.
Hi T.,
I am not a doctor or a nurse, but I dont think the Mirena affects the thyroid or cause Hypothyroidism at all. Yes it has hormones, but it is not the underlying cause.
I too have been diagnosed with hypothyroidism, also known as Hashimotos disease after giving birth to my son. My doc prescribed me Synthroid which is a hormone replacement drug, but I still suffer from the effects of hypothyroidism.
You can read up more on hypothyroidism/hashimotos here: http://www.medicinenet.com/hashimotos_thyroiditis/article...
and here http://www.hashimotosdiseasesymptoms.com/
Here is a snippet of the first article, just to give you an idea:
"Hashimoto's thyroiditis and/or Hypothyroidism is a condition caused by inflammation of the thyroid gland. It is an autoimmune disease, which means that the body inappropriately attacks the thyroid gland--as if it was foreign tissue. The underlying cause of the autoimmune process still is unknown."
Side effects: http://thyroid.about.com/cs/hypothyroidism/a/checklist.htm
PS. Candice you are right, just because you have been diagnosed with hypothyroidism does NOT mean you have hashimotos... Ask your doctor if you are not sure.