hyperkalsemia

Hypercalcemia is a biochemical condition in which there is an elevated level of calcium in the blood. It is typically defined as a total serum calcium above 10.5 mg/dL (2.62 mmol/L) or an elevated ionized calcium. Mild elevations may be asymptomatic and detected incidentally, while more substantial increases can cause a range of symptoms and complications.

The most common causes are primary hyperparathyroidism and malignancy-associated hypercalcemia. Other causes include excessive vitamin D intake or production, granulomatous diseases such as sarcoidosis, certain medications (notably thiazide diuretics and lithium), prolonged immobilization, renal failure, and familial hypocalciuric hypercalcemia. Hypercalcemia can be categorized as PTH-dependent, where parathyroid hormone is elevated or inappropriately normal, or PTH-independent, where PTH is suppressed and other mechanisms drive the calcium rise (PTH-related peptide from tumors, increased 1,25-dihydroxy vitamin D, or reduced renal calcium excretion).

Clinical features range from vague fatigue and weakness to more specific effects such as polyuria, polydipsia, constipation, abdominal pain, bone pain, and psychiatric symptoms. In severe cases, confusion, delirium, or coma and cardiac arrhythmias may occur.

Diagnosis starts with confirming elevated calcium and adjusting for albumin if needed. Measurement of intact PTH helps classify the cause. If PTH is elevated, primary hyperparathyroidism is favored; if suppressed, investigations focus on PTHrP, vitamin D status, and malignancy workup. Additional tests include kidney function, phosphate, magnesium, and targeted imaging as indicated.

Management depends on severity and cause. Mild, asymptomatic hypercalcemia may be observed with removal of contributing factors. Acute or symptomatic cases require aggressive IV hydration with normal saline, discontinuation of offending drugs, and agents that reduce bone resorption such as bisphosphonates or denosumab. Calcitonin can provide rapid, short-term relief. Treatment of the underlying cause, such as parathyroidectomy for primary hyperparathyroidism or cancer-directed therapy for malignancy, is essential. In severe renal failure, dialysis may be necessary. The term hyperkalsemia is a misspelling; the correct term is hypercalcemia.