Asymptomatic Primary Hyperparathyroidism

The clinical profile of primary hyperparathyroidism (PHPT) as it is seen in the United States and most Western countries has evolved significantly over the past half century. The introduction of the multichannel serum autoanalyzer in the 1970s led to the recognition of a cohort of individuals with asymptomatic hypercalcemia, in whom evaluation led to the diagnosis of PHPT. The term "asymptomatic primary hypeparathyroidism" was introduced to describe patients who lack obvious signs and symptoms referable to either excess calcium or parathyroid hormone. Although it was expected that asymptomatic patients would eventually develop classical symptoms of PHPT, observational data suggest that most patients do not evolve over time to become overtly symptomatic. In most parts of the world, the asymptomatic phenotype of PHPT has replaced classical PHPT. This report is a selective review of data on asymptomatic PHPT: its demographic features, presentation and natural history, as well as biochemical, skeletal, neuromuscular, psychological, and cardiovascular manifestations. In addition, we will summarize available information on treatment indications and options for those with asymptomatic disease.