As that is occurring, the gland produces a diminishing amount of
thyroid hormone, and the TSH starts rising in response. To offset the loss,
thyroid med is required to keep your serum thyroid levels high enough to prevent symptoms. Also, be aware that Free T3 correlates best with hypo symptoms, while Free T4 and TSH do not correlate well at all. Another thing to note is that when taking adequate thyroid medication, the TSH is frequently suppressed below range.