Hypercalcemia is too much calcium in the blood.
Calcium is important to many body functions, including:
- Bone formation
- Hormone release
- Muscle contraction
- Nerve and brain function
Parathyroid hormone (PTH) and Vitamin D help manage calcium balance in the body. PTH is made by the parathyroid glands, which are four small glands located in the neck behind the thyroid gland. Vitamin D
is obtained when the skin is exposed to sunlight, and from dietary sources such as:
- Egg yolks
- Fortified cereals
- Fortified dairy products
Primary hyperparathyroidism is the most common cause of hypercalcemia. It is due to excess PTH release by the parathyroid glands. This excess occurs due to an enlargement of one or more of the parathyroid glands, or a growth on one of the glands. (Most of the time, these growths are not cancerous).
Other conditions can also cause hypercalcemia:
- An inherited condition that affects the body's ability to regulate calcium (familial hypocalciuric hypercalcemia)
- Being bed-bound (or not being able to move) for a long period of time (this occurs most often in young people)
- Calcium excess in the diet. This is called milk-alkali syndrome. It is most often due to at least 2,000 milligrams of calcium per day. Taking too much vitamin D may add to the problem.
- Kidney failure
- Medications such as lithium and thiazide diuretics (water pills)
- Some cancerous tumors (for example, lung cancers, breast cancer)
- Some infectious and inflammatory diseases such as tuberculosis, Paget's disease and sarcoidosis
Hypercalcemia affects fewer than 1 in 100 people. The condition is most often diagnosed at an early stage, so most patients have no symptoms.
Women over age 50 (after menopause) are most likely to have hypercalcemia. In most cases, this is due to primary hyperparathyroidism.
Exams and Tests
An accurate diagnosis is needed in hypercalcemia. Patients with kidney stones should have tests to evaluate for hypercalcemia.
Treatment is aimed at the cause of hypercalcemia whenever possible. People with primary hyperparathyroidism (PHPT) may need surgery to remove the abnormal parathyroid gland. This will cure the hypercalcemia.
People with mild hypercalcemia may be able to monitor the condition closely over time.
Severe hypercalcemia that causes symptoms and requires a hospital stay may be treated with the following:
- Diuretic medication, such as furosemide
- Drugs that stop bone breakdown and absorption by the body, such as pamidronate or etidronate (bisphosphonates)
- Fluids through a vein (intravenous fluids) - this is the most important therapy
- Glucocorticoids (steroids)
How well you do depends on the cause of hypercalcemia. The outlook is good for people with mild hyperparathyroidism or hypercalcemia with a treatable cause. Most of the time, there are no complications.
Patients with hypercalcemia due to conditions such as cancer or granulomatous disease may not do well. This is most often due to the disease itself, rather than the hypercalcemia.
These complications of long-term hypercalcemia are uncommon today.
When to Call a Medical Professional
Contact your health care provider if you have:
Family history of hypercalcemia
Family history of hyperparathyroidism
Symptoms of hypercalcemia
Most causes of hypercalcemia cannot be prevented. Women over age 50 should see their health care provider regularly and have their blood calcium level checked if they have symptoms of hypercalcemia.
Talk to your health care provider about the correct dose for calcium and vitamin D supplements if you are taking these medicines.
Bringhurst R, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 28.
Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 253.
Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.