Q: On a routine blood test, my serum calcium was high, and my doctor found that my parathyroid hormone level was elevated. For now, he’s just watching things. What is the implication of this? – K.W., Philadelphia
A: With all the talk these days about calcium and osteoporosis, you might think that a disorder that causes an increased level of calcium in the blood would be a good thing. But our bodies like balance. There’s a narrow range of calcium in the blood that’s needed for your muscle cells (including heart muscle) to contract and function properly, for clotting, for proper nerve function and for certain enzymes to activate normally. Too much calcium in the blood can cause confusion, constipation, kidney stones, nausea, excess urination, dehydration, muscle weakness and bone pain.
Parathyroid hormone, or PTH, is secreted by four pea-size glands in the neck, just behind the thyroid gland. A fall in blood calcium (or a rise in blood phosphorus) triggers PTH release.