The Intact Parathyroid Hormone (iPTH) test measures the level of the biologically active form of parathyroid hormone in the blood. Parathyroid hormone (PTH) is produced by the parathyroid glands and plays a crucial role in regulating calcium and phosphorus levels in the body, as well as maintaining bone health.

Unlike older PTH tests, the iPTH test specifically measures the full-length hormone, providing a more accurate assessment of parathyroid function.