Thyroid values ​​(thyroid hormones) and TSH

As a thyroid levels refers to hormones that are produced by the thyroid produced like T3 and T4. The activity of the thyroid is controlled by the hormone TSH ('thyroid stimulating hormone') from the pituitary gland.

If the thyroid produces too many hormones, the pituitary gland secretes less TSH.

If the thyroid gland works 'too slowly', the pituitary gland tries to stimulate the thyroid by secreting more TSH, which then leads to an increased TSH level.

By determining the levels of the pituitary hormone TSH and the Thyroid hormones T3 and T4 in the blood can therefore be used to determine both an overactive and an underactive thyroid.