1.   An underactive thyroid, or hypothyroidism, can cause feelings of depression.

2.   Either an underactive thyroid or overproduction of thyroid hormone can also contribute to an erectile problem.

3.   The study compared four versions of levothyroxine, a hormone replacement given to about eight million Americans with underactive thyroids.

4.   Unfortunately, about half of those with underactive thyroids do not know they have a definable and treatable problem.

5.   Underactive thyroid, or hypothyroidism, which slows the metabolism.

6.   An underactive thyroid -- hypothyroidism -- is by far the most common problem.

7.   In addition to heart trouble, he had an underactive thyroid, internal bleeding and severe anemia.

8.   These may be an advantage as well for underactive thyroid.