What happens if one of your parathyroid glands is damaged?

Three more remaining: There are four parathyroid glands situated in the neck, behind the thyroid gland -- two on left and two on right, usually a few centimeters apart. These glands make parathyroid hormone (PTH) that control calcium and bone metabolism. Usually only 0.5 to 1 parathyroid is sufficient to make enough pth. If 3 to 3.5 glands are damaged or removed, the body can still maintain PTH and calcium control.

Nothing: You only need one parathyroid gland to be fine!

Redundancy: You only need one functioning parathyroid to lead a healthy normal life. This anatomical fact makes thyroid surgery largely safe. Sometimes parathyroids can be removed or damaged during thyroidectomy.