Understanding thyroid tests
The thyroid gland is a vital endocrine (hormone-producing) gland that plays a major role in chemical reactions in the body (our metabolism). It is located at the front of the neck, below the voice box, and is butterfly-shaped. The thyroid gland produces the thyroid hormones triiodothyronine (T3) and thyroxine (T4), among other things.
These thyroid hormones have various functions: They are responsible for the metabolism, growth and development of the body. The production of the thyroid hormones is regulated by the pituitary gland (hypophysis). The pituitary gland makes a hormone called TSH (thyroid-stimulating hormone). TSH not only stimulates the production of thyroid hormones – it also influences the size of the thyroid gland.
TSH production, in turn, is inhibited by the thyroid hormones. The system can be compared to a thermostat, which makes sure that the room temperature is kept at a certain value. So the concentration of thyroid hormones in the blood is usually fairly constant.
There are different tests and examinations to check the function and characteristics of the thyroid gland.