Medically Reviewed By William C. Lloyd III, MD, FACS
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What is hypercalcemia?

Calcium is an essential mineral that plays a vital role in many different bodily functions. For example, strong bones require constant metabolism of calcium to generate bone matrix. The healthy parathyroid glands regulate the amount of calcium that circulates in the blood. Hypercalcemia is a condition in which the blood has too much calcium. Calcium is a mineral that is essential for many aspects of health, including the health of bones and teeth and a normal heart rhythm. Calcium is also required for muscle contractions and relaxation, nerve and hormone function, and blood pressure regulation.

Calcium must be consumed in your diet, absorbed by your digestive system, and eliminated or removed from your body effectively, in order to maintain optimal health. Most people get calcium by eating a variety of foods rich in calcium. Foods that naturally contain calcium include milk and other dairy products; green, leafy vegetables; seafood; nuts; and dried beans. Calcium is also added to orange juice, breakfast cereals, breads, and other fortified food products. After consuming these sources of calcium, the body then eliminates excess or unused calcium through urine, stool and sweat.

Hypercalcemia occurs when the body does not effectively regulate and eliminate calcium. Hypercalcemia is most commonly caused by primary hyperparathyroidism, a condition in which the parathyroid glands, which are located in the neck, overproduce parathyroid hormone (PTH). PTH is one of the main regulators of calcium, along with vitamin D. Certain types of cancer can also cause hypercalcemia, especially breast and lung cancer. The National Cancer Institute estimates that 10% to 20% of patients with cancer will develop hypercalcemia (Source: NCI).

Hypercalcemia is often mild and does not produce symptoms, so you may only become aware of high blood calcium levels through a laboratory test. When symptoms are noticeable, they can include excessive urination, fatigue, nausea and vomiting, decreased appetite, excessive thirst, bone pain, and abdominal or flank pain.

Untreated hypercalcemia can lead to serious complications, such as osteoporosis, kidney stones, kidney failure, and bone fractures. Seek regular medical care and follow your treatment plan to reduce the risk of serious long-term complications from hypercalcemia. Seek immediate medical care (call 911) if you, or someone you are with, are unable to walk normally after a fall or other injury, or have severe flank or abdominal pain, which may occur with bloody urine or an inability to urinate.

What are the symptoms of hypercalcemia?

Hypercalcemia is often mild and does not cause symptoms. When symptoms become noticeable, they can vary depending on the severity, type and stage of the underlying disease, and individual factors, such as your age.

General symptoms of hypercalcemia

High blood calcium can involve the following symptoms:

Psychological or neurological symptoms that may occur with hypercalcemia

High blood calcium may accompany symptoms related to the nervous system or psychiatric conditions including:

Symptoms that might indicate a serious or life-threatening condition

Hypercalcemia may occur with symptoms that might indicate a serious or life-threatening condition, such as kidney stones, kidney failure, or serious depression, which should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these symptoms including:

  • Bloody urine

  • Chest pain or palpitations

  • Confusion, disorientation, decreased alertness, lethargy, or loss of consciousness

  • Inability to urinate or severely reduced urination

  • Inability to walk normally after a fall or other injury

  • Severe flank or abdominal pain

  • Talking about or having thoughts of harming oneself or committing suicide

What causes hypercalcemia?

The most common cause of hypercalcemia is primary hyperparathyroidism. This condition occurs when the parathyroid glands overproduce parathyroid hormone (PTH), which causes the body to retain calcium.

Common causes of hypercalcemia

Hypercalcemia, or high blood calcium, may be caused by a wide variety of conditions and diseases including:

  • Adrenal gland failure

  • Anorexia

  • Certain medications, especially thiazide diuretics (“water pills”) or lithium

  • Dehydration

  • Excess vitamin D

  • Hyperthyroidism (overactive thyroid)

  • Kidney disease or failure

  • Primary hyperparathyroidism (overproduction of parathyroid hormone by the parathyroid glands)

  • Specific cancers including some types of lung and breast cancers

  • Vomiting associated with eating disorders such as bulimia

Rare causes of hypercalcemia

Hypercalcemia can also be caused by less common conditions including:

  • Familial hypocalciuric hypercalcemia (condition in which insufficient calcium is excreted)

  • Overabundance of calcium in the diet

  • Rare cancers

Serious or life-threatening causes of hypercalcemia

In some cases, hypercalcemia may be a symptom of a serious or life-threatening condition. These conditions include:

What are the risk factors for hypercalcemia?

A number of factors increase the risk of developing hypercalcemia. They include:

  • Dietary intake of more than 2,000 milligrams (mg) of calcium per day

  • Female gender older than 50 years

  • Immobility, such as being bedridden (bones can become underused and release calcium into the blood)

  • Inadequate fluid intake, leading to or worsening dehydration

How is hypercalcemia treated?

Prompt diagnosis and treatment of hypercalcemia reduces the risk of developing serious complications, such as osteoporosis and kidney failure. Treatment involves rebalancing the body’s calcium levels, as well as treating the underlying cause and any associated complications. Treatments may include:

  • Diuretics such as furosemide (Lasix), which work differently from thiazide diuretics

  • Fluid replacement

  • Medications that prevent bone breakdown such as calcitonin (Fortical, Miacalcin)

  • Surgical removal of the parathyroid glands

In severe cases, treatment of hypercalcemia and its complications may include hospitalization, close monitoring in an intensive care unit, intravenous administration of medications and fluids, or dialysis.

What are the potential complications of hypercalcemia?

Complications of hypercalcemia can be serious and even life threatening. You can best treat hypercalcemia and minimize the risk of complications by following the treatment plan you and your healthcare professional design specifically for you. Potential complications of hypercalcemia include:

  • Bone fractures

  • Cardiac disease (calcified valves and blood vessels)

  • Chronic bone pain

  • Cognitive changes, such as problems concentrating, changes in behavior, and impaired memory

  • Dehydration

  • Depression

  • Kidney failure

  • Kidney stones

  • Osteoporosis

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 19
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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