[Hyper- and hypocalcemia: what should you watch out for?].

Calcium is essential for numerous metabolic processes and is hormonally controlled. These hormonal mechanisms are surprisingly effective in regulating calcium levels very reliably within a narrow range - but deviations in serum calcium levels quite often cause clinical problems. Hypercalcemia predominantly occurs in primary hyperparathyroidism or is associated with tumors (especially osteolytic processes). Hypocalcemia is usually due to hypoparathyroidism (75% surgical, 25% primary) or vitamin D deficiency. Causal calcium management requires identification of the etiology of the disorder. Symptomatic therapy depends on the severity of the electrolyte imbalance. Calcium is lowered in hypercalcemia via forced diuresis, the administration of calcitonin and bisphosphonates or denosumab, if necessary, via dialysis. Severe hypocalcemia is corrected acutely with parenteral calcium administration and any further treatment decisions and prognosis depend on the underlying disease.