Hyperparathyroidism
Causes
The most common abnormality (about 90% of cases) that causes this, is a benign tumor (Parathyroid Adenoma) in one of the parathyroid glands. Yet another common cause is Parathyroid Hyperplasia (enlargement of all parathyroid glands). This problem may be associated with the genetic disorder Multiple Endocrine Neoplasia (MEN). In rare instances, primary hyperparathyroidism can develop from the presence of multiple adenomas and even more rarely from parathyroid cancer (1% of cases).
