TSH, or thyroid-stimulating hormone, is a hormone produced by the pituitary gland located at the base of the brain. Its primary role is to regulate the thyroid gland's production of thyroid hormones, mainly thyroxine (T4) and triiodothyronine (T3)
. The thyroid gland is a small, butterfly-shaped gland in the neck that controls many vital body functions by regulating metabolism, energy use, heart rate, digestion, mood, and more through the hormones it produces
. TSH works by binding to receptors on thyroid cells, stimulating the thyroid to absorb iodine and produce T3 and T4 hormones. These hormones then regulate the body's metabolic rate and other important functions. The levels of TSH in the blood provide feedback to the pituitary gland to adjust hormone production accordingly-if thyroid hormone levels are low, TSH increases to stimulate more production; if thyroid hormone levels are high, TSH decreases
. TSH levels are commonly measured in blood tests to assess thyroid function. High TSH levels usually indicate an underactive thyroid (hypothyroidism), while low TSH levels suggest an overactive thyroid (hyperthyroidism)
. In summary, TSH is a key hormone that signals the thyroid gland to produce hormones essential for regulating metabolism and overall body function, and its measurement is crucial for diagnosing thyroid disorders
