Hyperthyroidism (cont.)

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What are thyroid hormones?

Thyroid hormones stimulate the metabolism of cells. They are produced by the thyroid gland. The thyroid gland is located in the lower part of the neck, below the Adam's apple. The gland wraps around the windpipe (trachea) and has a shape that is similar to a butterfly formed by two wings (lobes) and attached by a middle part (isthmus).

The thyroid gland removes iodine from the blood (which comes mostly from a diet of foods such as seafood, bread, and salt) and uses it to produce thyroid hormones. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3) representing 99.9% and 0.1% of thyroid hormones respectively. The hormone with the most biological activity (for example, the greatest effect on the body) is actually T3. Once released from the thyroid gland into the blood, a large amount of T4 is converted to T3 - the more active hormone that affects the metabolism of cells.

Thyroid Gland illustration - Hyperthyroidism
Thyroid Gland illustration - Hyperthyroidism
Medically Reviewed by a Doctor on 5/8/2014

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