Calcium Metabolism Part 2: Hyper and Hypocalcemia Diagnosis and Management

So of course I said earlier, treat the underlying cause.

So what are gonna be those causes of hypercalcemia? So notice like my coloring of this here on the pink side is PTH mediated and on the dark blue side is non PTH mediated.

So what are going to be things under PTH mediated? Number one has to be primary hyperparathyroidism.

And we're going to talk about that in the next slide.

So this is going to be someone who has a very high level of PTH.

They're going to have hypercalcemia.

They're going to have a low serum phosphate.

And that's primary hyperparathyroidism.

Right below that, I put down secondary hyperparathyroidism.

And what's going to distinguish those two is going to be the serum calcium.

And in secondary, serum calcium is going to be on the normal to low side, normal to low, normal to low.

And what's going to happen when your serum calcium is normal to low, it's going to increase PTH.

So of course, there's a secondary hyperparathyroidism.

Right below that, what a surprise, is tertiary hyperparathyroidism.

And once again, I'm going to have another slide in just a moment.

But when do I think about this? People who have end-stage renal disease on hemodialysis, and we're going to talk about some of the physiology behind that in one second.

But these are going to be the classic PTH-mediated primary, secondary, and tertiary hyperparathyroidism.

Right below that, I put hyperfamilial, hypocalceric hypercalcemia.

So this is going to be individuals where even though serum calcium is going to be elevated, the calcium in the urine is going to be low.

And that's weird.

So look at my first bullet point under FHH is that the minute we think it's going to be FHH, you must, must, must rule out primary hyperparathyroidism.

So of course, they're going to look exactly the same.

Why? PTH is going to be elevated, the serum calcium will be elevated.

But what's going to be the distinguishing factor is that urine calcium.

In primary hyperparathyroidism, you're going to have lots of calcium in the urine.