The thyroid is a butterfly-shaped gland located in the front of the neck below the adams apple. Its primary function is to regulate metabolism, which is the body’s ability to break down food and convert it to energy. The thyroid does this by producing two hormones—triiodothyronine (T3) and thyroxine (T4)—that influence nearly all of the metabolic processes in your body. Thyroid hormone production is regulated by thyroid-stimulating hormone (TSH), which is made by the pituitary gland which is located in the brain.
The parathyroid glands are four pea-sized glands located behind the thyroid gland and which produce parathyroid hormone (PTH). This hormone helps regulate calcium and phosphorous levels in the bloodstream.