High Calcium Levels in Cancer Patients

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Doctors refer to elevated levels of calcium in the blood as hypercalcemia. This condition occurs as a complication of cancer, particularly in cases of lung cancer, breast cancer, neck cancer and head cancer.

The National Cancer Institute reports that hypercalcemia occurs in 10 to 20 percent of all adults who have cancer. Hypercalcemia also affects 0.5 to one percent of all children with cancer. This complication occurs most often in the presence of solid tumors and malignancies of the blood.


Several factors influence the amount of calcium in the blood of cancer patients. Osteolytic hypercalcemia occurs when a primary or secondary tumor destroys bone, allowing the bone cells to release calcium into the bloodstream. Humoral hypercalcemia occurs when malignant cells cause the body to reabsorb calcium from the bone. Hypercalcemia also occurs when the kidneys do not excrete excess calcium from the body.

Contributing Factors

Cancer patients have several factors that influence the amount of calcium in the blood. Lack of physical activity, nausea, vomiting and dehydration can increase calcium levels. Since cancer patients often experience fatigue, vomiting and nausea after chemotherapy or radiation treatments, there is a greater risk of hypercalcemia in this population.

Signs & Symptoms

Signs and symptoms of high calcium levels in the blood include constipation, nausea, vomiting, fatigue, malaise, frequent urination and pain. Without treatment, hypercalcemia also causes irregular heartbeat and may lead to coma.


Hypercalcemia associated with cancer differs significantly from hypercalcemia caused by primary hyperparathyroidism and other medical conditions. Cancer-related hypercalcemia progresses rapidly, appears suddenly and often results in an increased erythrocyte sedimentation rate, which indicates inflammation in the body.


Since the symptoms of hypercalcemia mimic other cancer symptoms, doctors may have difficulty diagnosing this condition. Hypercalcemia symptoms also closely resemble the effects of chemotherapy and radiation treatments. If a doctor recognizes the signs and symptoms of hypercalcemia, a simple blood test determines the amount of calcium in the blood. The National Institutes of Health reports that normal calcium levels range from 8.5 to 10.2 mg/dL (milligrams per decliter).


Doctors design hypercalcemia treatment plans to remove excess calcium from the blood and restore calcium levels to normal. Diuretics, also known as water pills, increase the amount of calcium excreted in the urine. Examples of diuretics include bumetanide, hydrochlorothiazide and furosemide. Drugs.com indicates that Pamidronate helps treat the bone damage caused by cancer. This restores the balance between the formation of bone and the breakdown of bone cells. Supportive care measures include medications to control nausea and vomiting, prevention of slips and falls, pain medications and the prevention of accidental injury.