I had multinodular goitre with normal TSH. Taken Levothyroxine for 12 months. 2 months after stopping the tablets TSH is increasing. Why?

Question

Dear doctor,

I had multinodular goiter with normal TSH. I was taking Levothyroxine tablet daily for 12 months. Now, two months after completing the tablets, my TSH is 11.5 (max 5.5). Why?

Answer 1

Hi,

Welcome to icliniq.com.

As long as you were taking Levothyroxine, your body levels of T3, T4 hormones were maintained at normal levels.

Due to your goiter, your body is not producing T3, T4 hormones adequately. But, that is getting compensated by excessive synthesis of TSH (thyroid-stimulating hormone) which stimulates the body to produce T3, T4.

Once you take Levothyroxine, your body levels of T3, T4 hormones will be maintained at normal levels and the stimulus for TSH secretion decreases and hence TSH comes to normal.

But, once you stop taking Levothyroxine, the T3, T4 levels come down and body starts producing more and more TSH to compensate low T3 and T4.

My advice is to continue taking Levothyroxine and let your TSH come to normal, then let us plan to reduce the dose later. This may take a few months to years.

For further queries consult an endocrinologist online.