Hypercalcemia - Definition and Overview

Hypercalcaemia is an elevated calcium level in the blood. It can be an asymptomatic laboratory finding, but because an elevated calcium level is often a clue to other serious disease, a diagnosis should be undertaken if it persists.

Signs and symptoms

Hypercalcemia per se can result in fatigue, depression, confusion, anorexia, nausea, vomiting, constipation, or increased urination; if it is chronic it can result in urinary calculi (renal stones or bladder stones). Abnormal heart rhythms can result, and an EKG finding of a short QT interval suggests hypercalcemia. Symptoms are more common at high calcium levels (12.0 mg/dL or 3 mmol/l). Severe hypercalcemia (above 15-16 mg/dL or 3.75-4 mmol/l) is considered a medical emergency: at these levels, coma and cardiac arrest can result.

Causes

• abnormal parathyroid gland function
  • primary hyperparthyroidism
    • solitary adenomas
    • multiple endocrine neoplasia (MEN)
  • lithium use
  • familial hypocalciuric hypercalcemia
• malignancy
  • solid tumor with metastasis (e.g. breast cancer)
  • solid tumor with humoral mediation of hypercalcemia (e.g. lung or kidney cancer)
  • hematologic malignancy (multiple myeloma, lymphoma, leukemia)
• vitamin-D metabolic disorders
  • hypervitaminosis D (vitamin D intoxication)
  • elevated 1,25(OH)₂D levels (e.g. sarcoidosis and other granulomatous diseases)
  • idiopathic hypercalcemia of infancy
  • "rebound" hypercalcemia after rhabdomyolysis
• disorders related to high bone-turnover rates
  • hyperthyroidism
  • prolonged immobilization
  • thiazide use
  • vitamin A intoxication
• renal failure
  • severe secondary hyperparathyroidism
  • aluminum intoxication
  • milk-alkali syndrome

Treatments

Definitive treatment is directed at the underlying cause. Emergency treatment consists of intravenous hydration, increased salt intake, use of diuretics, and in extreme cases such drugs as biphosphonates or calcitonin.

See also

• Calcium metabolism
• Hypocalcaemia