Parathyroid hyperplasia is a form of hyperparathyroidism in which all four glands are overactive. In the most common form of primary hyperparathyroidism, a patient will have one or two parathyroid adenomas, benign tumors that grow from the parathyroid glands. But some patients have hyperplasia, which is not caused by parathyroid tumors. It is simply an enlargement and overactivity of all of the parathyroid glands. The symptoms are the same as in the “classic” type of primary hyperparathyroidism. We diagnose it the same way. And the treatment is the same: remove the bad glands, leaving behind enough to maintain normal calcium levels. If there is one adenoma and three normal glands, we will remove the adenoma and leave the other glands in place. If all four glands are diseased (hyperplasia), then we need to remove three glands and a part of the fourth, leaving behind a piece that is large enough to maintain normal calcium levels. We never want to remove all four glands, since this will make someone permanently hypOparathyroid, which causes its own problems. The long-term prognosis is the same. Parathyroid hyperplasia is just a different form of primary hyperparathyroidism. The only difference is what happens in the operating room. You can expect the same benefits from surgery as someone who had a tumor removed.