This is a research study to investigate cardiovascular health in people with mild hyperparathyroidism. Previous research has suggested that severe hyperparathyroidism may be associated with abnormalities in the heart and blood vessels. It is unclear whether mild hyperparathyroidism affects cardiovascular health. This study involves the investigation of the heart and blood vessels of people with mild hyperparathyroidism. Various non-invasive laboratory and radiological test to assess cardiovascular and bone health will be done at set intervals over the course of 2 years. It is our hypothesis that patients with primary hyperparathyroidism will have subtle abnormalities in their cardiovascular system. Using state-of-the art techniques that are sufficiently sensitive to detect these subtle abnormalities, we will define cardiovascular features of this disease that have, up to now, eluded clear definition. We expect taht the extent of these findings will be related to the severity of the underlying primary hyperparathyroidism. We further hypothesize that cardiovascular manifestations may regress with successful cure of the hyperparathyroid state.