</font><blockquote><div id="quote"><font class="small">Quote:</font>
The smooth control of thyroid hormone levels that physicians achieve by using pure thyroxine preparations is due to the slow rate at which thyroxine is used up by the body. In fact, if a normal person's thyroid suddenly stopped working, it would take about seven days for the body to use up just half of the T4 already in the blood. Therefore, if you are hypothyroid and taking thyroxine tablets to correct your thyroid deficiency, you will not feel suddenly sick even if you stop your thyroxine tablets abruptly. Furthermore, because you won't notice a sudden change in the way you feel, you may incorrectly assume that your thyroid condition no longer exists and you may stop taking your medication entirely. Unfortunately, when your hypothyroidism does recur, its onset may be so gradual that you may not realize that you are becoming ill again until your symptoms are pronounced.

</div></font></blockquote><font class="post"> From: http://www.tsh.org/disorders/hypothy...deractive.html