What is the primary function of thyroid hormones?

The primary function of thyroid hormones, which include thyroxine (T4) and triiodothyronine (T3), is to regulate metabolism, growth, and development. These hormones play a crucial role in how the body uses energy, influencing the basal metabolic rate and affecting almost every organ's function.

Thyroid hormones stimulate the metabolism of carbohydrates, proteins, and fats, which contributes to overall energy production and utilization in the body. They are essential for normal growth and development, particularly in children, where adequate thyroid hormone levels are necessary for brain development and physical growth. In adults, these hormones help maintain a stable metabolism, affect heart rate, and are involved in thermoregulation.

While blood pressure regulation is influenced by thyroid hormones, it is not their primary function. Similarly, calcium absorption is predominantly managed by parathyroid hormone and vitamin D, rather than thyroid hormones. Water retention is often affected by aldosterone and antidiuretic hormone (ADH), rather than being a direct action of thyroid hormones. Therefore, the most accurate representation of the primary function of thyroid hormones is their regulation of metabolism, growth, and development.