Primary hyperparathyroidism: Diagnosis and treatment

Ally Prebtani, MD, is a professor of medicine in the Division of Endocrinology and Metabolism at McMaster University.

How to diagnose and treat primary hyperparathyroidism?

Ally Prebtani, MD: To make the diagnosis of primary hyperparathyroidism, you need a high calcium and high parathyroid hormone (PTH) [levels] and you have to rule out other causes of a mildly elevated PTH and a mildly elevated calcium.

Those 2 important causes to rule out include something called familial hypercalcemic hypocalciuria. And you also have to think about a couple of drugs that can also do the same. And the 2 most common drugs that can cause a mild elevation in PTH and calcium are lithium and thiazide or thiazide-like diuretics.

Once you’ve ruled that out, then the next test you want to do to for sure rule out those 2 conditions is you want to do a 24-hour urine calcium. And based on that, you can do something called a fractional excretion of calcium. That will determine or help you sort out whether this is primary hyperparathyroidism or a condition, which is benign, called familial hypercalcemic hypocalciuria.

And once you make the diagnosis of primary hyperparathyroidism, then you have to determine whether this patient should go for surgery or not go for surgery because the most common cause of primary hyperparathyroidism is either a parathyroid adenoma or, less likely, parathyroid hyperplasia.