Your Thyroid Gland

What is the Thyroid?

The thyroid gland, or thyroid, is located at the base of the neck just below the Adam’s apple. It is the shape of a butterfly. One wing, or “lobe,” of the thyroid is located on each side of the trachea (often referred to as the “windpipe”).1

The Function of the Thyroid is to:

Produce and Store Thyroid Hormones2

The thyroid gland produces and stores 2 hormones - T3 and T4. These hormones affect almost every cell in the body1.

Release them into the bloodstream2

The activity of the thyroid gland is regulated by the pituitary gland through the release of thyroid stimulating hormone (TSH)1.

Thyroid hormones regulate vital body functions3

The feedback system involving the hypothalamus, pituitary, and thyroid5

The pituitary gland controls the amount of thyroid hormones produced by the thyroid. The pituitary is located at the base of the brain. Another part of the brain, the hypothalamus, helps the pituitary do its job.

The hypothalamus produces thyroid releasing hormone (TRH), which stimulates the pituitary to release thyroid stimulating hormone (TSH). TSH stimulates the thyroid to release thyroid hormones.

The Hypothalamus and the Pituitary Glands Affect Thyroid Function3,4

The pituitary, hypothalamus and thyroid all work together in a feedback loop to control the amount of thyroid hormones in the body.2, 5

The system works similarly to the way a thermostat controls the temperature in a room. Just as the thermometer in a thermostat senses the temperature of a room, the hypothalamus and pituitary gland sense the amount of thyroid hormones in the bloodstream.

  • If the level is low, the pituitary releases TSH to signal the thyroid to “turn on the heat” by producing more thyroid hormones.
  • If the level is high, the pituitary decreases TSH production to “turn down the heat.”


Thyroid Cancer Glossary

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Low-Iodine Diet

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Doctor Discussion Guide

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