Hypercalcemia is an abnormally high amount of calcium in the blood. Calcium is a mineral your body needs that can affect your nerves, muscles, digestive tract, kidneys, and your heart. When your calcium level gets too high, you may have unusual symptoms.

The calcium level in your blood is controlled by hormones, your kidneys, your gastrointestinal tract, and bone. Hypercalcemia may happen because cancer has spread to your bones, which causes calcium to be released. Or the cancer cells may make hormones that affect the systems controlling the amount of calcium in your blood. Hypercalcemia is not caused by drinking too much milk or by eating too many dairy products. The symptoms may come on slowly. Or they may happen in a short period of time.

Certain cancers are more likely to cause hypercalcemia. These include lung cancer, breast cancer, kidney cancer, head and neck cancers, gastrointestinal cancers, lymphoma, multiple myeloma, and leukemia.

Symptoms of hypercalcemia can be a lot like symptoms of other health problems and medicine side effects. You and your loved ones should know which signs and symptoms might mean that your calcium level is getting too high.

It's important to let your doctor know if you have any of the following, especially if they're different from the way you usually feel:

• Extreme tiredness (fatigue)
• Excessive sleepiness
• Confusion
• Trouble thinking
• Depression
• Muscle pain or weakness
• Loss of appetite
• Nausea
• Vomiting
• Stomach pain
• Constipation
• Headache
• Frequent urination
• Excessive thirst
• Dry mucous membranes (the lining of your mouth and throat)

Severe symptoms include:

• Seizures
• Coma
• Changes in your heartbeat (too slow or too fast)
• Heart attack
• Kidney failure

Changes in the calcium level in your blood are linked to the cancer. So the best way to control the calcium is to treat the cancer itself. Your doctor will talk with you about this.

Some people have symptoms when the calcium level is only slightly high. Others may not have symptoms until the level is extremely high. Medicines can be used to help control your calcium level—even if the cancer is not being treated.

If your calcium level is high and you're having many problems, you may need to be in the hospital for a short period of time. If it is only mildly high, you might be able to control it at home. The decision of when to treat hypercalcemia is often based on your symptoms, not your blood calcium level.

If you have mildly high calcium levels and few or no symptoms, treatment may include the following:

• You may need to drink more fluids to help your kidneys take calcium out of your blood.
• You may have fluids put right into your blood through a vein (I.V.) if you can't drink a lot.
• Your calcium levels and symptoms will be closely watched.

For higher calcium levels, or if you are having symptoms, you may need to stay in the hospital. You can expect the following:

• Extra fluids will be given into your blood through a vein (I.V.).
• You may be given calcium-controlling medicines or steroids. These are used to stop bone from breaking down and releasing calcium.
• You may have to take a hormone called calcitonin. It's used to decrease calcium release from your bones and increase calcium removal in your kidneys.
• You will have frequent blood draws. These will be done to check your levels of calcium and other chemicals.
• If you have kidney failure, you may need dialysis.

Here is what to expect:

• Blood draws may be needed.
• Drink plenty of fluid daily (unless your doctor tells you not to).
• Take medicines as directed.
• Tell your doctor right away if you have any symptoms or symptoms of hypercalcemia that get worse.