Originally Posted by Lady50
I have heard that if you have had hypoT for a long time the TSH can be suppressed. Can you tell me if that is true?
I believe it to be true. My TSH at diagnosis was 2.6, but my Free T3 and Fere T4 were low in their respective scales. It seems that after long-term hypothyroidism without treatment, the body gets used to a lower level of hormoen and the hypothalamus and pituitary decide that this is an OK arrangement.
I dont' have proof, other than ancecdotal stories, but that's enough to convince me. Dr. Dommisse mentions something similar in his Optimal Treatment paper:
Normally, the anterior pituitary will secrete enough TSH to maintain adequate thyroid hormone levels. When this fails to occur, either grade-1-primary or secondary hypothyroidism is considered to be present. There seem to be subtle, conventionally called 'subclinical', failures of the anterior pituitary to produce sufficient TSH in response to low thyroid hormone levels that cannot be explained solely by the traditional form of secondary hypothyroidism (secondary to a pituitary tumor or outright pituitary failure, as in Sheehan's Syndrome: postpartum hemorrhage or infarction of the pituitary gland). This could also be due to a tertiary hypothyroidism (where the thyrotropin-releasing hormone ~ TRH ~ from the hypothalamus fails, for poorly-understood reasons, to stimulate the anterior pituitary to secrete adequate amounts of TSH), or to a TSH_specific hidden hypopituitarism.
I believe that long-term untreated hypo can be one of the causes of this. It is my belief that Hypothyroidism slows EVERYTHING down eventually--including the Hypothalamus and the Pituitary.