This test measures the level of parathyroid hormone (PTH) in the blood. PTH, also known as parathormone, is made by your parathyroid glands. These are four pea-sized glands in your neck. PTH controls the level of calcium in the blood. Calcium is a mineral that keeps your bones and teeth healthy and strong. It's also essential for the proper functioning of your nerves, muscles, and heart.
If calcium blood levels are too low, your parathyroid glands will release PTH into the blood. This causes calcium levels to rise. If calcium blood levels are too high, these glands will stop making PTH.
PTH levels that are too high or too low can cause serious health problems.
A PTH test is most often used along with calcium testing to:
Diagnose hyperparathyroidism, a condition in which your parathyroid glands produce too much parathyroid hormone
Diagnose hypoparathyroidism, a condition in which your parathyroid glands produce too little parathyroid hormone
Find out whether abnormal calcium levels are being caused by a problem with your parathyroid glands
Monitor kidney disease