source: American Thyroid Association summary/abstract:
What is the Thyroid Gland?
The thyroid gland located in the neck produces thyroid hormones which help the body use energy, stay warm and keep the brain, heart, muscles, and other organs working normally.
Thyroid Hormone is Used:
• to replace the function of a failing, or failed, thyroid gland (replacement therapy), and
• to prevent further growth of thyroid tissue (suppression therapy), particularly in patients with a history of thyroid cancer
Why do I Need Thyroid Hormone Pills?
Hypothyroidism is the most common reason for needing thyroid hormone replacement (see Hypothyroidism brochure). Pure synthetic thyroxine (T4), taken once daily by mouth, successfully treats the symptoms of hypothyroidism in most patients.