PTH
Parathyroid hormone (PTH) is a hormone that the parathyroid glands make and release to control the level of calcium in the blood. PTH also helps control the levels of phosphorus and vitamin D in the blood and bones.
Why it matters: A provider can check parathyroid hormone levels with a blood test, which providers and laboratories call "PTH, intact". PTH keeps blood calcium levels in check so that the nerves, muscles and heart can function properly: it triggers the release of small amounts of calcium from the bones into the bloodstream, enables the production of active vitamin D in the kidneys, signals the kidneys to keep calcium in the body rather than passing it out in urine, and signals the small intestine to absorb more calcium from food. High PTH levels, known as hyperparathyroidism, cause high blood calcium and low blood phosphorus. Low PTH levels, known as hypoparathyroidism, cause low blood calcium and high blood phosphorus.
Source · Cleveland Clinic — what it is, why it matters, what moves it
May increase with:
May decrease with:
What is PTH?
Parathyroid hormone (PTH) is a hormone that the parathyroid glands make and release to control the level of calcium in the blood. PTH also helps control the levels of phosphorus and vitamin D in the blood and bones.
What might a high or low PTH mean?
A provider can check parathyroid hormone levels with a blood test, which providers and laboratories call "PTH, intact". PTH keeps blood calcium levels in check so that the nerves, muscles and heart can function properly: it triggers the release of small amounts of calcium from the bones into the bloodstream, enables the production of active vitamin D in the kidneys, signals the kidneys to keep calcium in the body rather than passing it out in urine, and signals the small intestine to absorb more calcium from food. High PTH levels, known as hyperparathyroidism, cause high blood calcium and low blood phosphorus. Low PTH levels, known as hypoparathyroidism, cause low blood calcium and high blood phosphorus.
What is the typical reference range for PTH?
The general-population reference range shown here is 1.6 – 6.9 pmol/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect PTH?
It may be higher with: Low blood calcium, which triggers parathyroid hormone release, Parathyroid cancer, Parathyroid adenoma, Kidney disease. It may be lower with: High blood calcium, which prevents the glands from releasing PTH, Accidental damage to the parathyroid glands during neck or thyroid surgery, Certain genetic and autoimmune conditions.