Hyperparathyroidism can be either primary, secondary or tertiary. The majority of patients will have primary hyperparathyroidism (pHPT) which involves a disease state where one or more of the parathyroid glands (there are usually four) begin to secrete excessive amounts of parathyroid hormone (PTH). PTH acts on a variety of organ systems to increase blood calcium levels. This can be achieved by increasing resorption from bone, elevating absorption from the gut and altering excretion through the kidneys. This leads not only to elevated levels of calcium in the blood but also impacts on the organ systems that are affected by chronic exposure to elevated PTH and calcium levels. This duality of problems cannot be overstated primarily because many patients with pHPT will not experience symptoms, but still require management to avoid silent end organ problems that can be a significant health problem.
It is not uncommon for the diagnosis to be made incidentally, when a blood test reveals the presence of hypercalcaemia. It can also often be difficult to ascertain if symptoms are truly present given that they can be very non-specific. Fatigue, lethargy, malaise, insomnia, low energy levels, fluctuating mood and trouble concentrating are the typical hallmarks of symptomatic disease but are also very common amongst the general population.
More obvious symptoms are generally a reflection of the end organ effects of pHPT. Excessive bone resorption can result in reduced bone density and predispose to fractures. Elevated calcium levels can also impact on the kidneys and lead to kidney stones and reduced kidney function. Impaired cardiac function and high blood pressure can also be associated with pHPT.
Many of these effects are silent but will take a toll over many years of unrecognised disease, or disease that is managed sub-optimally. Generally, the diagnosis of pHPT is an indication for surgery given that the disease cannot be cured any other way. Medical management can help reduce the impact of the disease but it cannot be resolved entirely without surgery. Every patient with this diagnosis should see a specialist endocrine surgeon for an opinion and early referral to an ANZES recognised endocrine surgeon will facilitate an optimal outcome.
