The parathyroid glands are endocrine glands in the neck, the size of a pea. Most people have 4 parathyroid glands on the thyroid gland; however, some people have up to 5 or more. The function of the parathyroid gland is totally different from the thyroid. Produce parathyroid hormone (PTH), which helps the body maintain the balance between calcium and phosphorus. Disorders occur when the parathyroid gland produces excessive amounts of hormone or scarce, upsetting the balance. If there is too much PTH hyperparathyroidism occurs, increasing the level of calcium in blood. But if not produce enough PTH, the imbalance is called hypoparathyroidism, taking blood too little calcium and excessive phosphorus.