Results

The long-term effects of thyroidectomy depend on how much of the thyroid is removed.

Partial thyroidectomy

If only part of your thyroid is removed, the remaining portion typically takes over the function of the entire thyroid gland. So you might not need thyroid hormone therapy.

Complete thyroidectomy

If your entire thyroid is removed, your body can't make thyroid hormone. Without replacement, you'll develop signs and symptoms of underactive thyroid (hypothyroidism). Therefore, you'll need to take a pill every day that contains the synthetic thyroid hormone levothyroxine (Synthroid, Unithroid, others).

This hormone replacement is identical to the hormone normally made by your thyroid gland and performs all of the same functions. Your doctor will test your blood to know how much thyroid hormone replacement you need.