Overview of Hypercalcemia

High calcium levels can be life threatening

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Hypercalcemia, which is an elevated calcium level in the blood, is a serious situation. High blood calcium is not common, but it can develop due to medical illnesses like kidney failure or cancer.

Hypercalcemia can cause vague effects, such as a loss of appetite and fatigue. If it becomes severe or persistent, high calcium levels can affect your muscles and heart rate.

Your calcium level can be measured with a simple blood test, and excess calcium can be managed with procedures that lower calcium levels. If you are prone to high calcium, you may need to have your levels monitored on a regular basis to prevent the unwanted and dangerous effects of the condition.


Many of the symptoms of hypercalcemia are vague. The symptoms of chronically high calcium differ from those of acute, sudden elevations in calcium level. Additionally, mildly elevated calcium produces different effects than severely elevated calcium.

Symptoms of mild hypercalcemia include:

  • Nausea
  • Vomiting
  • Loss of appetite
  • Abdominal pain
  • Constipation
  • Fatigue

Symptoms of severe hypercalcemia include:

  • Increased thirst
  • Dehydration
  • Decreased urination
  • Muscle cramping, twitching, or weakness
  • Irregular heart rate
  • Confusion, hallucinations, or personality changes
  • When severe, coma and death

Symptoms of chronic hypercalcemia (usually mild) include:

If you have kidney disease or cancer, you should become familiar with the symptoms of hypercalcemia. Sometimes, however, hypercalcemia comes on without a warning, and you might not expect or recognize the symptoms.


There are several causes of high calcium. The most common of these are bone breakdown, kidney problems, and hyperparathyroidism. There are several illnesses that can cause these conditions to develop.

Causes of hypercalcemia include:

  • Blood cell cancers: Lymphoma and leukemia can both interfere with bone formation and break down bones, releasing excess calcium into the blood.
  • Kidney failure: The kidneys are responsible for filtering your blood to get rid of excess materials, including calcium. Kidney failure can lead to excess calcium.
  • Hyperparathyroidism: The four parathyroid glands, located adjacent to the thyroid gland in your neck, make parathyroid hormone (PTH). This hormone acts on the kidneys to prevent too much calcium from being excreted. High PTH results in hypercalcemia. You can develop high PTH due to a parathyroid over-activity or a parathyroid tumor.
  • Metastatic cancer: Cancer that spreads to the bone (such as breast cancer and prostate cancer) causes the bone to break down, releasing calcium into the blood.

If you are healthy, you won't get hypercalcemia by eating too much dairy. Your thyroid gland makes a hormone, calcitonin, that keeps your blood calcium level from getting too high.

How Calcium Affects Your Body

Calcium is an essential mineral that helps your muscles contract. If you have excessive calcium, your muscles may twitch or cramp. Even more importantly, your heart muscle can be affected by excess calcium, resulting in an irregular heartbeat.


Generally, hypercalcemia is detected based on a blood test. If you have hypercalcemia, there is certainly a medical cause for it. Your medical team may order some other tests to help identify the causative problem.

You may need blood tests, a urine test, imaging tests, or a biopsy.

Blood and Urine Tests

  • Complete blood count (CBC): This test can help identify changes that correspond to lymphoma or leukemia
  • Serum electrolytes: You may have other electrolyte abnormalities, such as alterations in sodium, potassium, magnesium, or phosphorous (also regulated by PTH) This test can help your doctors identify a parathyroid or kidney problem.
  • Urine test: When kidney failure is considered, a urine test can help determine how well your kidneys are working.
  • Parathyroid level: Your parathyroid hormone can be detected by a blood test.

Imaging Tests

  • Kidney computerized tomography (CT) or ultrasound: If there is concern about your kidneys, you may need an imaging test to evaluate them.
  • Parathyroid imaging test: If there is a concern about your parathyroid glands, you may need to have an imaging test that visualizes these glands.
  • Bone scan: Because cancer can metastasize to the bone, a bone scan can help identify metastatic lesions.


  • Bone marrow biopsy: A bone marrow biopsy can help your medical team with the diagnosis of lymphoma or leukemia.

Even if you don't have signs of heart irregularities, you will probably need an electrocardiogram (EKG) so your doctor can monitor your heart rhythm before you develop any problems.


The treatment of hypercalcemia varies depending upon how elevated your calcium is, as well as the cause. Medical approaches that are used to decrease blood calcium level include medications and interventions.

And management of the primary problem that caused hypercalcemia is an important part of your treatment.

Strategies for treating hypercalcemia include:

  • Staying hydrated, particularly if you have a condition that predisposes you to hypercalcemia
  • Intravenous (IV) fluids, to dilute calcium in the blood if necessary

Medications used to treat hypercalcemia include:

  • Bisphosphonates, which decrease bone breakdown
  • Calcimar (calcitonin) is used as a medication to lower elevated calcium levels
  • Gallium nitrate is used to treat cancer-related hypercalcemia
  • Sensipar (cinacalcet) lowers calcium in the blood
  • Steroids may be used in some situations, although steroids can also lower calcium in some instances, so steroid use depends on the cause of your hypercalcemia

Intervention may be necessary for managing hypercalcemia:

  • Dialysis is a process by which your blood is filtered with a machine to eliminate waste material. You may need to have dialysis if your hypercalcemia is very severe.

A Word From Verywell

Hypercalcemia is rare because your body does a good job of maintaining control of your calcium concentration. However, illnesses can make it difficult for your body to keep up with excess calcium.

If you are prone to hypercalcemia, it is a good idea to meet with a dietitian, stay hydrated, and have your calcium level checked regularly.

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