- Thyroid Stimulating Hormone (TSH)
Located in the front of the neck, the thyroid is small, butterfly-shaped gland that creates three primary hormones – triiodothyronine (T3), thyroxine (T4) and calcitonin. The release of these hormones controls numerous different bodily functions, including metabolism and growth.
A thyroid-stimulating hormone (TSH) test measures the amount of TSH in the blood. TSH is produced by the pituitary gland, which is located at the base of your brain and is responsible for regulating the amount of hormones released by the thyroid. The thyroid produces more hormones if the pituitary gland produces more TSH.
Often performed to determine the underlying cause of abnormal thyroid hormone levels, a TSH test is also used to screen for an underactive or overactive thyroid gland. Your physician may order a TSH test if you’re experiencing symptoms of a thyroid disorder, which can be categorized as either hypothyroidism (the thyroid produces too few hormones) or hyperthyroidism (the thyroid produces too many hormones).