Hypercalcaemia

What is hypercalcaemia?

The parathyroid glands are pea-shaped glands, four in number, present on the thyroid gland in the neck. The parathyroid glands secrete the parathyroid hormone that regulates the calcium level in the body. Hyperparathyroidism is a condition characterized by excessive secretion of parathyroid hormone (PTH), into the bloodstream. Over secretion of the parathyroid hormone results in increased levels of calcium in the bloodstream, also known as hypercalcemia. Primary hyperparathyroidism is the most common cause of hypercalcemia.

What are the causes of hypercalcaemia?

Hypercalcemia can be classified into parathyroid mediated and non-parathyroid mediated hypercalcemia. The commonest cause of hypercalcemia is hyperparathyroidism or excess secretion of the parathyroid due to enlargement of one or more of the parathyroid glands or over activity of the parathyroid gland. The causes of non-parathyroid hypercalcemia include presence of malignancy, other endocrinal disorders such as adrenal disorder or hyperthyroidism, any inherited condition that affects the calcium metabolism, kidney failure, certain diseases such as tuberculosis, lung infection or sarcoidosis, certain drugs and intake of high calcium and vitamin D dietary supplements. Other causes of hypercalcemia include prolonged immobilization and dehydration.

What are the signs & symptoms of hypercalcaemia?

In cases of mild hypercalcemia, the patient may not experience any signs or symptoms or experience only a few symptoms. In severe cases, patient may develop certain symptoms such as nausea, vomiting, loss of appetite, excessive thirst, polyuria or frequent urination, constipation, abdominal pain, muscle weakness, pain in the joint and muscles and fatigue.

How is hypercalcaemia diagnosed?

Diagnosis of hypercalcemia is based on blood tests for serum calcium, PTH, vitamin D levels, and elevated blood levels of parathyroid hormone as well as tests for urine calcium. In the cases of non-parathyroid mediated hypercalcemia other tests such as chest X-ray, mammogram, CT or MRI scan may be used to diagnosis underlying cause.

What are the treatment options of hypercalcaemia?

The treatment of hypercalcaemia depends upon the severity and the underlying cause of hyperparathyroidism. The common treatment options for the management of hypercalcaemia include:

• Regular exercise
• Medication such as bisphosphonates and calcitonin to reduce calcium levels in the blood stream
• Avoid certain medications such as thiazide-type diuretics
• Increased intake of fluid to prevent the formation of kidney stones

In severe cases of hypercalcemia, hospitalization is required to reduce serum calcium levels to protect the kidneys and bones. The treatment includes intravenous fluids, loop diuretic medications, calcitonin, glucocorticoids and haemodialysis or peritoneal dialysis.

Parathyroid medicated hypercalcaemia is best managed with surgery. This is generally recommended for patients below 50 years of age or with complications associated hypercalcaemia.