Thyroid Function Tests : Interpretation

Thyroid function tests (TFTs) are critical tools in the diagnosis and management of thyroid disorders, offering valuable insights into the functioning of this vital gland. The thyroid gland plays a pivotal role in metabolic regulation, influencing numerous physiological processes in the body. TFTs typically include measurements of Thyroid Stimulating Hormone (TSH), Triiodothyronine (T3), Thyroxine (T4), and thyroid antibodies.

TSH, secreted by the pituitary gland, regulates thyroid hormone production. T3 and T4 are the primary hormones produced by the thyroid gland, directly influencing metabolism, growth, and development. Thyroid antibodies, such as anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies, are used to detect autoimmune thyroid diseases.

Interpreting TFTs involves understanding the intricate balance between these hormones and their feedback mechanisms. TSH levels typically move inversely with T3 and T4 levels due to their feedback on the pituitary gland. For instance, in primary hypothyroidism, the thyroid gland's reduced hormone production leads to elevated TSH levels as the pituitary tries to stimulate the gland. Conversely, in hyperthyroidism, high levels of thyroid hormones suppress TSH secretion.

The interpretation of these tests requires careful correlation wit

A quick recap on the normal functioning of the gland

• Thyroid Gland Function: Produces thyroid hormones, primarily thyroxine (T4)...