Hypercalcemia is a common sign of multiple myeloma, characterized by high calcium levels in the blood. Ten percent to 15 percent of people have hypercalcemia when they are first diagnosed with multiple myeloma. More than 1 out of 4 people with multiple myeloma have high calcium levels at some point over the course of their disease.

What Is Hypercalcemia?

Hypercalcemia refers to a person having high levels of calcium. Calcium is a mineral that makes the bones stronger, helps bones grow, controls levels of hormones, and supports healthy tissues and organs. Too much calcium can cause:

• Bone damage or breaks
• Kidney damage
• High blood pressure
• Slow heartbeat
• Impaired mental functioning

Doctors measure calcium levels with a blood test. Multiple myeloma is not the only condition that causes hypercalcemia. Other cancers also lead to this condition. Additionally, high calcium levels can develop because of medications, dehydration, or certain endocrine disorders.

Symptoms of Hypercalcemia

Many people with high calcium levels don’t have any symptoms. Others with more severe hypercalcemia can experience:

• Tiredness or weakness
• Feeling very thirsty
• Having to urinate often
• Nausea or vomiting
• Constipation
• Bone pain
• Feeling confused or depressed
• Heart palpitations
• Fainting

If you notice any of these symptoms, talk to your doctor. A simple blood test can show whether any of these symptoms are caused by abnormal calcium levels.

Hypercalcemia and Multiple Myeloma

Multiple myeloma is one of several conditions that affects the plasma cells (a type of white blood cell). It is important to check calcium levels in people with plasma cell disorders. Calcium levels help doctors diagnose myeloma and affect a person’s prognosis (outlook).

Myeloma Diagnosis

There are three stages of plasma-cell disorders: monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma. All of these disorders cause increased levels of plasma cells or abnormal antibodies. Certain signs of organ damage signal to a doctor that a person has full-blown multiple myeloma rather than MGUS or SMM. Signs of organ damage caused by myeloma are called CRAB symptoms, with CRAB standing for:

• Calcium levels that are high
• Renal dysfunction (kidney problems)
• Anemia (low levels of red blood cells) or low platelet counts (cells that help clot the blood)
• Bone lesions (damage, tumors, or abnormalities in the bone)

People with MGUS and SMM do not have CRAB symptoms, including hypercalcemia. If a person with one of these conditions develops high calcium levels, it is a sign that their condition has turned into multiple myeloma.

Hypercalcemia and Prognosis

People with multiple myeloma who are hypercalcemic have a worse prognosis than those with normal calcium levels. In one study, people with hypercalcemia lived an average of 40 months after being diagnosed with myeloma. Those without hypercalcemia lived for 57 months. High calcium levels are often a sign that treatment isn’t working or that the myeloma has relapsed (come back after being treated).

Why Does Myeloma Lead to Hypercalcemia?

Researchers believe that people with multiple myeloma have high calcium levels because of bone disease. Normally, the body balances the breakdown of old bone with the formation of new bone. However, multiple myeloma activates osteoclasts — cells that break down bone. People with multiple myeloma have bone that is weakened and dissolves faster than new bone is produced. As the bone breaks down, it releases calcium into the blood.

Kidney problems may also cause abnormal calcium levels in people with multiple myeloma. Myeloma cells make high levels of abnormal proteins, which damage the kidneys. Usually, the kidneys remove extra calcium from the blood. They often can’t perform this job as well in people with multiple myeloma.

Treatment for Hypercalcemia

Doctors use different treatments for hypercalcemia depending on how severe it is. Some cases of hypercalcemia don’t cause any symptoms. Other times, people have severe hypercalcemia that may be life-threatening if not treated.

Treating Mild Hypercalcemia

If calcium levels aren’t high enough to cause symptoms, doctors may recommend drinking extra fluids. This can help flush extra calcium out of the body.

Treating Moderate or Severe Hypercalcemia

For many people with myeloma, drinking extra fluids is not enough to treat hypercalcemia. In order to get more liquids into the body, doctors may recommend intravenous fluids. Corticosteroids can also help the body absorb less calcium and encourage the kidneys to remove more of this mineral. Another option is dialysis, in which blood is taken out of the body, cleaned, and then replaced. Dialysis may help the kidneys work better for people with renal failure.

Most people with myeloma need to take additional medications to help balance calcium levels. These medications block osteoclasts and reduce bone resorption (breaking down of the bones). These may include:

• Bisphosphonates, including Aredia (pamidronate) and Zometa (zoledronic acid)
• Miacalcin (calcitonin)
• Xgeva (denosumab)

If you have hypercalcemia and multiple myeloma, your doctor will likely recommend hypercalcemia treatments in addition to myeloma treatments. Talk to your doctor if you have any new or worsening symptoms that may be related to high calcium levels.

Talk With Others Who Understand

MyMyelomaTeam is the social network for people with multiple myeloma and their loved ones. On MyMyelomaTeam, more than 11,500 members come together to ask questions, give advice, and share their stories with others who understand life with multiple myeloma.

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