Parathyroid glands are very small glands that help regulate the body’s calcium levels, through the production of Parathyroid Hormone. However, there are many diseases that can disrupt this process. High levels of calcium and high levels of Parathyroid Hormone may be indicative of Primary Hyperparathyroidism, Secondary Hyperparathyroidism, Hyperplasia, Parathyroid Cancer, Multiple Endocrine Neoplasia, or DiGeorge Syndrome.