The parathyroid is a small gland located at the base of the front of the neck, near the thyroid. This gland produces parathyroid hormone (PTH), which controls levels of calcium and phosphorous in the blood.

Parathyroid cancer causes the parathyroid to make too much PTH, increasing the amount of calcium in the blood. People with a family history of parathyroid tumors or a hereditary condition called multiple endocrine neoplasia (MEN) type 1 or 2 have a greater risk of developing this type of cancer. Symptoms include a lump in the neck, bone pain, kidney problems, and other disorders related to having too much calcium in the blood.