The parathyroid glands are four (sometimes five) tiny glands in the neck that regulate the level of calcium in the blood, helping to strike a balance between the calcium levels in the blood and in the bones. Primary hyperparathyroidism may occur when one or more of the glands becomes enlarged and produces too much parathyroid hormone which will result in an elevated level of calcium in the blood. Secondary hyperparathyroidism occurs when blood calcium levels are chronically low, often due to kidney problems or intestinal problems or surgery. These processes will also cause a loss of calcium from the bones. This imbalance in the calcium levels may lead to osteoporosis and fractures, bone pain, kidney stones, fatigue, high blood pressure, mental changes, among other symptoms. Medications may help lower the calcium level but will not treat or cure the underlying problem. Surgery is the only definitive treatment to cure the disease. Surgery may entail removal of one or more, or all of the parathyroid glands.