What dies the thyroid gland produces

• The thyroid gland produces hormones called thyroxine (T4) and triiodothyronine (T3). These hormones stimulate the growth of the developing child and

increase the metabolic rate of the body (the rate at which energy is consumed). Thyroid disease can result in either under active (hypothyroidism) or

overactive (hyperthyroidism) gland.

• The thyroid is controlled by the pituitary, part of the brain, which secretes thyroid stimulating hormone (TSH) that stimulates the thyroid gland to secrete T3

and T4.

• T3, T4 and TSH can be measured in the blood and give us a very accurate picture of whether the gland is over or under active. These tests are called

‘thyroid function tests’


• Calcitonin is another thyroid hormone produced by C cells. Together with parathyroid hormone it regulates blood calcium levels.