Hypercalcemia: Symptoms, Causes, and Treatment

Hypercalcemia is the medical term for too much calcium in the blood. The body controls calcium levels by changing the way it takes it from bone or filters it through the kidneys. Certain conditions and circumstances can disrupt these processes, leading to high calcium levels. People with mild cases might feel normal, but moderate or high levels of calcium can often cause symptoms. And in severe cases, this condition can be life-threatening. We’ll cover the different causes of hypercalcemia, associated symptoms, medical complications, and treatment. 

What causes hypercalcemia? 

More than 90% of all cases of hypercalcemia are the result of two conditions — hyperparathyroidism and cancer. 

Hyperparathyroidism

Hyperparathyroidism occurs when the parathyroid gland makes too much hormone. The parathyroid gland sits right behind the thyroid gland in the neck. It releases parathyroid hormone, which plays a critical role in bone metabolism and the control of calcium levels. When there’s too much of it in the body, calcium levels start to rise. 

Cancer

Cancer can increase calcium in the blood by spreading to bone and breaking it down.  It can also release proteins that work just like parathyroid hormone. Certain kinds of cancer are more likely to lead to high calcium, such as:

• Hodgkin’s lymphoma

• Leukemia

• Multiple myeloma

• Breast cancer

• Kidney cancer 

• Cancer in the head and neck 

Other causes

There are other causes of hypercalcemia, though they are less common. These include:

• Severe dehydration

• Medications, such as lithium, thiazide diuretics, and tamoxifen

• Milk-alkali syndrome, which might happen if you take too many calcium antacids like calcium carbonate (TUMS)

• Immobility, which can lead to bone destruction

• Infections, such as tuberculosis and leprosy 

• An excess of vitamin A or D

• Hyperthyroidism

• Kidney failure

• Rhabdomyolysis

• Adrenal insufficiency

• Familial hypocalciuric hypercalcemia, a rare genetic condition 

What are the symptoms of hypercalcemia?

Mild cases of hypercalcemia may not cause any symptoms. But the higher the calcium level, the more likely you’re to notice side effects. The severity of symptoms is also related to how quickly the calcium level goes from normal to high. You might not notice any difference if you’ve been living with this condition for a long period of time — or if your calcium levels increase very slowly. 

Some of the symptoms you might notice include:

• Fatigue and malaise

• Muscle weakness

• Loss of appetite

• Nausea and vomiting

• Constipation

• Increased thirst

• Increased urination

• Bone pain

• Mood changes or depression

• Disorientation or confusion

A high calcium level in the blood can also lead to other medical conditions, including:

• Kidney stones and gallstones, although this could be more related to underlying problems with the parathyroid gland than the calcium level itself

• Pancreatitis

• Peptic ulcer disease

• Bradycardia (slow heartbeat)

• High blood pressure

How do you diagnose hypercalcemia? 

Hypercalcemia is easy to diagnose with blood tests. The normal range is typically 8.7 to 10.2 mg/dL, but this can vary from lab to lab. 

Very often medical providers find hypercalcemia by accident through routine screening, whether for your general checkup or to check on conditions like osteoporosis or kidney stones. 

How do you treat hypercalcemia?

Mild and even moderate cases of hypercalcemia that don’t cause symptoms may not need any emergent treatment. In these cases, the condition may resolve easily with good hydration. Your provider may suggest that you stop taking medications that could be contributing to the problem. 

More severe cases of hypercalcemia need a different treatment approach. This might be the case when your calcium level is extraordinarily high or you have severe symptoms like lethargy or confusion. In theses cases, treatment usually occurs in the hospital and includes:

• Intravenous (IV) fluids: to speed up hydration

• Furosemide (Lasix): a common diuretic that helps your kidneys remove the excess calcium

• Calcitonin (Miacalcin): a hormone that blocks the effects of parathyroid hormone

• Bisphosphonates: medications that prevent the breakdown of bone

• Prolia (denosumab): an alternative to bisphosphonates if you can’t tolerate them

Is hypercalcemia life-threatening? 

When hypercalcemia is severe, it’s an emergency and can be life-threatening. In most of these cases, there are other serious medical problems contributing to the problem. When the above treatments for severe hypercalcemia aren’t enough, your medical provider might consider adding hemodialysis to the treatment. This can get the calcium levels under control more efficiently. 

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Written by:

Robert Shafton, MD

Robert Shafton, MD, studied at the University of Michigan at Ann Arbor and Harvard University before earning his medical degree at the University of Illinois at Chicago. He trained at the Rambam Hospital in Haifa, Israel, during which specialized in urgent care medicine in the Tel Aviv area.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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