Parathyroid hormone (PTH) works to regulate the levels of calcium in the blood. PTH is synthesized in the four parathyroid glands which are located behind the thyroid. PTH is secreted into the bloodstream when calcium levels drop. PTH then normalises blood calcium levels by either taking calcium from the bones, activating Vitamin D in the kidney to promote calcium absorption from the intestines, or reducing the excretion of calcium into the urine. PTH will then decrease in response to the increasing blood calcium level.
PTH measurement may be relevant to the practitioner in hypercalcemia (high blood calcium levels) or hypocalcemia (low blood calcium levels). Hyperparathyroidism is a group of conditions that feature an overproduction or PTH by the parathyroid gland. Measurement of PTH can be used in monitoring of health issues that lead to long term imbalances in calcium or to monitor patients who are undergoing treatment for parathyroid tumours.
- Abnormal Calcium levels
- Diseases or conditions that affect calcium regulation
- Monitoring in Primary and Secondary hyperparathyroidism