The 4 parathyroid glands are located near or attached to the back side of the thyroid gland and produce parathyroid hormone (PTH). Parathyroid hormone regulates calcium, phosphorus, and magnesium balance within the blood and bone by maintaining a balance between the mineral levels in the blood and the bone.
Review Date 4/29/2022
Updated by: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.