Hypercalcemia - Causes and Symptoms

Definition

Hypercalcemia is defined as an increase in blood calcium levels compared to the norm; specifically, the total serum calcium (Ca) concentration is greater than 10.5 mg / dL (when it should be between 8.8 and 10.5 mg / dL).

The clinical features of hypercalcemia include constipation, anorexia, nausea, vomiting, musculoskeletal weakness and abdominal pain. The impairment of the renal concentration mechanism leads to polyuria, nocturia and polydipsia.

Prolonged or severe hypercalcaemia can lead to nephrocalcinosis (precipitation of calcium salts inside the renal parenchyma) and renal failure.

Usually, hypercalcaemia is consequent to an excessive bone reabsorption; the most common causes include hyperparathyroidism, vitamin D intoxication (especially due to inadequate intake) and malignant tumors with bone metastases (particularly those to the lung, breast, kidney and hematological malignancies such as multiple myeloma, leukemia and lymphoma) . Other associated disorders are hyperthyroidism and humoral neoplastic hypercalcemia (ie in the presence of non-metastatic tumors).

Patients forced to prolonged immobilization, for example with osteoporosis, multiple bone fractures and Paget's disease of the bones) are predisposed to hypercalcaemia, as well as subjects subjected to some therapies (eg treatment with thiazide diuretics, excess lithium or intoxication from theophylline).

Sometimes, the increase in the concentration of calcium in the blood is a consequence of vitamin A intoxication, kidney diseases (eg milk-alkali syndrome and tertiary hyperparathyroidism) or endocrine dysfunctions, such as Addison's disease and myxedema.

Hypercalcemia can also be the result of excessive absorption and / or gastro-intestinal calcium intake; this is the case of sarcoidosis and other granulomatous diseases (including berylliosis, coccidioidomycosis, histoplasmosis, leprosy, silicosis and tuberculosis).