RecruitingHypoparathyroidism Natural History StudyThis is a prospective three-year natural history study of adults with hypoparathyroidism. The goal is to monitor patients with hypoparathyroidism to define end-organ damage in the context of the disease. The study objectives are to: 1. Build a prospective cohort of patients to study HPT-associated end-organ damage. 2. Determine end-organ physiologic consequences of HPT. 3. Elucidate determinants of HPT-associated end-organ damage. Funding Source - FDA OOPD