Parathyroid Hormone (PTH) Test

A serum parathyroid hormone (PTH) test measures the level of this peptide hormone, which is secreted by the four parathyroid glands in the neck. PTH acts on the bones, kidneys, and intestines to increase blood calcium levels: it stimulates the release of calcium from bones, increases its reabsorption in the kidneys, and activates vitamin D to enhance its absorption in the intestines. It is ordered along with blood calcium levels to diagnose calcium and bone metabolism disorders.