• Excess PTH causes a high plasma calcium.
• Inadequate PTH causes a low plasma calcium
• Hypocalcemia can cause tetany and spasm and Chovstek's sign and Trousseaus sign may both be positive.
• Hypercalcemia can cause dehydration, mood and neurological change, abdominal symptoms and renal stones and tissue calcification.
• The commonest causes of hypercalcemia are primary hyperparathyroidism, malignancy and renal failure with tertiary hyperparathyroidism.
• The QT interval on the electrocardiograph is lengthened in hypocalcemia and shortened in hypercalcemia.

Interactive questions on this chapter

Go direct to answers and explanations

See other Chapters in this section

{Try the self-assessment to help learn this topic}

---

C. A. O'Callaghan 2004