Hypercalcemia

Hypercalcemia is serum calcium above 10.5 mg/dL (or ionized calcium above 5.3 mg/dL). The two most common causes are primary hyperparathyroidism and malignancy — together they account for roughly 90% of cases. Excess calcium depresses neuromuscular excitability, so the clinical picture is the opposite of hypocalcemia: decreased muscle tone, diminished deep tendon reflexes, and sluggish smooth muscle. The classic memory cue is 'bones, stones, groans, and moans' — bone pain, kidney stones, abdominal complaints (constipation, nausea, anorexia), and neurological changes (lethargy, confusion, coma). On ECG, look for a shortened QT interval — the heart repolarizes faster with excess calcium. Severe hypercalcemia (above 14 mg/dL) is a medical emergency. First-line nursing interventions center on aggressive IV normal saline hydration to promote renal calcium excretion. Loop diuretics (furosemide) may be ordered if the patient develops fluid overload or has heart failure — they are not used routinely. Thiazide diuretics are contraindicated because they increase renal calcium reabsorption. You also encourage mobility — immobility accelerates bone calcium release, worsening the problem. Monitor I&O carefully; the client is at risk for dehydration and renal calculi. Safety precautions are essential because lethargy and confusion increase fall risk.