Hypercalcemia

Definition

Hypercalcemia is too much calcium in the blood.

Causes, incidence, and risk factors

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 -- 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
• Fish
• 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 (usually not cancer) on one of the glands.

Other medical conditions can also cause hypercalcemia:

• Adrenal gland failure
• Being bedbound (or not being able to move) for a long period of time
• Calcium excess in the diet (called milk-alkali syndrome, usually due to at least 2,000 milligrams of calcium per day)
• An inherited condition that affects the body's ability to regulate calcium (familial hypocalciuric hypercalcemia)
• Hyperthyroidism
• Kidney failure
• Medications such as lithium and thiazide diuretics (water pills)
• Some cancerous tumors (for example, lung cancers, breast cancer)
• Vitamin D excess (hypervitaminosis D) from diet or inflammatory diseases

Hypercalcemia affects less than 1 percent of the population. The widespread ability to measure blood calcium since the 1960s has improved detection of the condition, and today most patients with hypercalcemia have no symptoms.

Women over age 50 are most likely to have hypercalcemia, usually due to primary hyperparathyroidism.

Symptoms

Abdominal:

• Constipation
• Nausea
• Pain
• Poor appetite
• Vomiting

Kidney:

• Flank pain
• Frequent thirst
• Frequent urination

Muscular:

• Muscle twitches
• Weakness

Psychological:

• Apathy
• Dementia
• Depression
• Irritability
• Memory loss

Skeletal:

• Bone pain
• Bowing of the shoulders
• Fractures due to disease (pathological fractures)
• Loss of height
• Spinal column curvature

Signs and tests

• Serum calcium
• Serum PTH
• Serum PTHrP (PTH-related protein)
• Serum vitamin D level
• Urine calcium

Treatment

Treatment is directed at the cause of hypercalcemia whenever possible. In more severe cases of primary hyperparathyroidism, surgery may be needed to remove the abnormal parathyroid gland and cure the hypercalcemia.

However, if your hypercalcemia is mild and caused by primary hyperparathyroidism, your health care provider will most likely recommend that you not have surgery, but will monitor your condition closely over time.

Severe hypercalcemia that causes symptoms and requires a hospital stay is treated with the following:

• Calcitonin
• Dialysis
• 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)
• Glucocorticoids (steroids)

Expectations (prognosis)

How well you do depends on the cause of hypercalcemia. Patients with mild hyperparathyroidism or hypercalcemia with a treatable cause do well and do not have complications.

Patients with hypercalcemia due to conditions such as cancer or granulomatous disease may not do well, but this is usually due to the disease itself, rather than the hypercalcemia.

Complications

Gastrointestinal

• Pancreatitis
• Peptic ulcer disease

Kidney

• Calcium deposits in the kidney (nephrocalcinosis)
• Dehydration
• High blood pressure
• Kidney failure
• Kidney stones

Psychological

• Depression
• Difficulty concentrating or thinking

Skeletal

• Bone cysts
• Fractures
• Osteoporosis

The complications of long-term hypercalcemia are uncommon today.

Calling your health care provider

Contact your physician or health care provider if you have:

• Family history of hypercalcemia
• Family history of hyperparathyroidism
• Symptoms of hypercalcemia

Prevention

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.

You can avoid hypercalcemia from calcium and vitamin D supplements by contacting your health care provider for advice about the dose if you are taking supplements without a prescription.

References

Bringhurst R, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 27.

Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 266.