In hypercalcemia, the level of calcium in blood is too high.
The body carefully controls the amount of calcium circulating in the blood (see see Overview of Calcium).
Causes of hypercalcemia include the following:
Symptoms and Diagnosis
Hypercalcemia often causes no symptoms. The earliest symptoms are usually constipation, nausea, vomiting, abdominal pain, and loss of appetite. People may excrete abnormally large amounts of urine, resulting in dehydration and increased thirst.
Very severe hypercalcemia often causes brain dysfunction with confusion, emotional disturbances, delirium, hallucinations, and coma. Muscle weakness may occur, and abnormal heart rhythms and death can follow. Long-term or severe hypercalcemia commonly results in kidney stones containing calcium. Less commonly, kidney failure develops, but it usually resolves with treatment. However, if enough calcium accumulates within the kidneys, damage is irreversible.
Hypercalcemia is usually detected during routine blood tests.
If hypercalcemia is not severe, correcting the cause is often sufficient. If people have mild hypercalcemia or conditions that can cause hypercalcemia and if their kidney function is normal, they are usually advised to drink plenty of fluids. Fluids stimulate the kidneys to excrete calcium and help prevent dehydration. Doctors may advise people to take mineral supplements containing phosphate, which helps prevent calcium absorption.
If the calcium level is very high or if symptoms of brain dysfunction or muscle weakness appear, fluids and diuretics are given intravenously as long as kidney function is normal. Dialysis is a highly effective, safe, reliable treatment, but it is usually used only for people with severe hypercalcemia that cannot be treated by other methods.
Several other drugs (including bisphosphonates, calcitonin, corticosteroids, and, rarely, plicamycin) can be used to treat hypercalcemia. These drugs work primarily by slowing the release of calcium from bone.
Hypercalcemia caused by cancer is particularly difficult to treat. If the cancer cannot be controlled, hypercalcemia usually returns despite the best treatment.
Last full review/revision July 2013 by James L. Lewis, III, MD