Hypercalcemia is an unusually high level of calcium in the blood. Hypercalcemia can be life threatening and is the most common metabolic disorder associated with cancer, occurring in 10% to 20% of people with cancer. Calcium is important for many bodily functions, including bone formation, muscle contractions, and nerve and brain function.


The symptoms of hypercalcemia often develop slowly and can be very similar to the symptoms of cancer or cancer treatments. The seriousness of symptoms is often unrelated to the actual level of calcium in the blood, and many patients have no symptoms at all. Older patients usually experience more symptoms than younger patients. People with hypercalcemia may experience the following symptoms:

  • Loss of appetite, nausea, and vomiting
  • Constipation and abdominal pain
  • Increased thirst and frequent urination
  • Tiredness, weakness, and muscle pain
  • Changes in mental status, including confusion, disorientation, and difficulty thinking
  • Headaches

Finally, severe hypercalcemia can be associated with kidney stones, irregular heartbeat or heart attack, and eventually loss of consciousness and coma.

Patient considerations

Hypercalcemia is a serious disorder and can be life threatening. Patients and their families should be familiar with the symptoms of hypercalcemia and report any symptoms to their doctor. Treatment not only improves symptoms, but also improves quality of life and may make it easier to complete cancer treatment.
In addition to getting treatment from your doctor, the following tips can help prevent hypercalcemia or prevent it from becoming worse:

  • Drink fluids
  • Control nausea and vomiting
  • Walk and be active, which helps prevent bone from breaking down
  • Check with your doctor before taking any medications, as some may make hypercalcemia worse

Note: Hypercalcemia is usually not related to having too much calcium in the diet, so reducing calcium intake by eating fewer dairy products and other high-calcium foods does not help.