Hypercalcemia is too much calcium in the blood.

Calcium is one of the most important minerals in the body. Most calcium is in the bones, but some is in the blood. Calcium works in the body in the following ways:

• Makes bones and teeth strong.
• Helps the heart, muscles, and nerves work.
• Helps blood clot.

The amount of calcium in the blood is normally controlled by hormones, the kidneys, and bone.

Hormones

Parathyroid hormone and calcitrol, are hormones that help balance the calcium level in the body.

• Parathyroid hormone helps calcium enter the bloodstream from the kidneys and bone.
• Calcitrol is a form of vitamin D. It helps the intestines absorb calcium.

Kidneys

Normal, healthy kidneys help the body keep the amount of calcium it needs. The kidneys can remove large amounts of calcium from the blood and pass the extra calcium into the urine.

Bone

Most of the calcium in the body is in bone, but bone has only a small role in keeping the balance of calcium in the body.

Hypercalcemia (too much calcium in the blood) is a very serious problem in cancer patients.

When calcium is out of balance, the whole body is affected. If hypercalcemia is not treated, it will get worse and can lead to a coma and death. Early diagnosis and treatment are very important and can be lifesaving and may help you continue your cancer treatment and improve your quality of life.

Hypercalcemia (too much calcium in the blood) is the most common life-threatening complication of cancer occurring in 10% to 20% of adults and rarely in children. Hypercalcemia occurs most often in patients with:

• Breast cancer.
• Lung cancer.
• Multiple myeloma.
• Lymphoma and other blood cancers.

A physical exam and lab tests are used to diagnose hypercalcemia.

The symptoms of hypercalcemia may occur slowly and may look like other illnesses, making it hard to diagnose. Early diagnosis and treatment may improve symptoms in a few days.

The following tests and procedures may be used:

• Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
• Neurological exam: A series of questions and tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro exam or a neurologic exam.
• Electrocardiogram (EKG): A recording of the heart's electrical activity to evaluate its rate and rhythm. A number of small pads (electrodes) are placed on the patient’s chest, arms, and legs, and are connected by wires to the EKG machine. Heart activity is then recorded as a line graph on paper. Electrical activity that is faster or slower than normal may be a sign of heart disease or damage.
• Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances, such as calcium, hormones, vitamin D, phosphate, and magnesium, released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of one or more of these substances can be a sign of hypercalcemia.
• Kidney function test: A test in which blood or urine samples are checked for the amounts of certain substances released by the kidneys. A higher or lower than normal amount of a substance can be a sign that the kidneys are not working the way they should. This is also called a renal function test.
• Urinalysis: A test to check the color of urine and its contents, such as sugar, protein, red blood cells, and white blood cells.