What is hypercalcemia?

Hypercalcemia, or higher than normal level of calcium in your blood, is a fairly common finding. Blood tests, such as those drawn for an annual physical exam, today routinely check calcium levels. This allows physicians to detect abnormally high calcium levels early.

Calcium is an important mineral in our bodies throughout our lifetime for bone growth, bone strength, maintaining proper hormone levels and optimal functioning of nerves, muscles and the brain. The calcium level is usually very carefully controlled by the body. However, certain medications and conditions can result in high blood calcium levels.

In the past, complications such as bone loss and fractures, kidney stones, kidney failure, hypertension and bradycardia (slowed heart rate), were commonly found as a result of longstanding untreated high calcium levels. These are now rarely seen thanks to blood tests that lead to preventive treatment.

What causes hypercalcemia?

Hypercalcemia can be caused by more than 25 separate diseases, several medications and even dehydration. Primary hyperparathyroidism and various kinds of cancers account for the greatest percentage of all patients with hypercalcemia.

In primary hyperparathyroidism, one or more of the four parathyroid glands, located behind the thyroid gland in your neck, produce too much parathyroid hormone. Normally, the parathyroid glands work with the kidneys, skeleton and intestines to carefully regulate the level of blood calcium. But sometimes a parathyroid gland becomes overactive, resulting in excess parathyroid hormone being released and an elevated blood calcium level.

Common medications such as hydrochlorothiazide and other thiazide diuretics (prescribed for hypertension and edema), lithium, and excessive intake of vitamin D, vitamin A or calcium can result in hypercalcemia. Taking too much calcium carbonate in the form of Tums® or Rolaids® is actually one of the more common causes of hypercalcemia.

Lung cancer, breast cancer and certain cancers of the blood can cause hypercalcemia that can become severe. Other less common causes of hypercalcemia include:

What are the symptoms of hypercalcemia?

Although having symptoms of hypercalcemia is uncommon, symptoms can include:

Last reviewed by a Cleveland Clinic medical professional on 07/02/2018.


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