Parathyroid Hormone (PTH) Test

This laboratory test measures the concentration of parathyroid hormone (PTH) in the blood serum. This hormone is secreted by the four parathyroid glands located in the neck behind the thyroid gland. PTH acts as a major regulator of blood calcium and phosphorus levels by stimulating the release of calcium from bones, increasing its absorption from the intestines, and decreasing its loss by the kidneys. It is usually measured in conjunction with blood calcium levels for accurate assessment.