High calcium - diagnosis and treatment

Having high calcium levels in your blood is called hypercalcaemia. It is a serious condition that sometimes happens when you have cancer.

The first test you will have is a blood test, you will go on to have other tests if you have a higher than normal amount of calcium in your blood. Your doctor will need to assess you, to make sure you get the right diagnosis and treatment.

Treatment aims to lower the amount of calcium in your blood and control any symptoms you have. 

Diagnosing high calcium

Your doctor might examine you. They will ask about your symptoms, how long you have had them and whether you:

  • are feeling or being sick
  • feel thirsty
  • passing urine more than usual
  • have lost your appetite
  • feel more tired than usual
  • feel confused
  • have pain

These questions might seem like a lot to deal with if you are not feeling very well at the time. But it is very important that your doctor takes the time to get all the information. Your family and friends might be able to answer questions if you are in too much pain or feeling too tired or sick.

Your doctor will measure your calcium levels with a blood test. You might also have other tests and investigations to see how well your kidneys are working. You may have an ECG test to see if your heart is affected by the high calcium level. You will need treatment if the test results show that you have high levels of calcium in your blood.

Can you prevent high calcium?

Having a high amount of calcium in your blood is a possible risk associated with advanced cancer. It is not really possible to prevent it from happening. It is not caused by anything in your diet so you shouldn't need to alter what you eat. 

Recognising the symptoms of high blood calcium is important so that you can ask your doctor for help as soon as possible. 

Treating high calcium

The tests will help the team caring for you understand what is causing the hypercalcemia. Treatment will include treating the cause. This includes treating your cancer.

The aims of treatment for high blood calcium are to lower the levels and relieve the symptoms. Your treatment will depend on the amount of calcium in your blood. You may need to spend some time in hospital to get your calcium levels down. 

You might have one or more of the following treatments. 

Fluids

Fluids through a drip help flush the extra calcium out of your system. Drinking plenty of fluids will help too if you can manage it.

Steroids

You might have steroids to help reduce your calcium levels. You may have them as tablets or into your bloodstream as an injection.

Bisphosphonates

Bisphosphonates (bis-fos-fon-ates) are drugs that help to get your calcium levels down. You can have these drugs through a drip into a vein or as tablets. Which type you need depends on how high your calcium levels are. Your doctor will decide on the best treatment for you.

Bisphosphonates can also help to reduce pain from cancer that has spread to the bone. They can also help to stop damaged bones breaking. You might have bisphosphonate tablets to take home to stop the calcium building up in your blood again.

Bisphosphonates can sometimes cause side effects. Tell your doctor if they make you feel unwell. They can also make your calcium level go too low (hypocalcaemia). This should be picked up by blood tests. It is also worth being aware of the possible symptoms of low calcium levels. For example, numbness or tingling in the feet and hands, and around the mouth.

Calcitonin

You might have another drug called calcitonin to help lower your blood calcium level. It can also help to stop the breakdown of bone. You have this drug as an injection. You might have it once a day or 3 or 4 times a day. How often you have it and for how long depends on:

  • how high your calcium level is
  • how well it works

You will have a blood test to check your calcium levels.

Denosumab

Denosumab (pronounced den-oh-sue-mab) is a type of targeted therapy called a monoclonal antibody. It is made in the laboratory to recognise and find specific proteins on the outside of some cells. This helps to stop the breakdown of the bones and allows them to strengthen. Denosumab is also known by its brand names, Xgeva and Prolia.

This drug is used to prevent fractures and other cancer related bone problems. It is recommended in adults with some types of cancer that have spread to the bones. You have it as an injection just below the skin. 

You might have denosumab if you have high calcium and bisphosphonates have not brought your calcium levels down. Or you might have it if you are unable to have bisphosphonates for a medical reason.

Other drugs

You might also have drugs to help relieve the symptoms of high calcium, such as sickness, constipation, pain or confusion.

Your doctor might suggest you stop taking other medications if they could be making your hypercalcaemia worse. These include:

  • calcium supplements
  • lithium (a type of mood stabiliser)
  • some medicines for heartburn and acid reflux
  • some water tablets (diuretics)

What treatment will I have?

The type of treatment you have depends on how high your calcium levels are and how severe your symptoms are.

For example, you have urgent treatment with fluids and bisphosphonate drugs if you have moderate to severe high calcium, or severe symptoms. You still need treatment, but less urgently, if it is mild high calcium. You might just need bisphosphonate treatment if you are able to drink plenty of fluids.

Treatment relieves some symptoms more quickly than others. For example, sickness, constipation and thirst are much easier to relieve than tiredness and loss of appetite.

It may not be possible to control high calcium if your cancer is very advanced and you are in the final days or weeks of life. But your doctors will do all they can to help make you as comfortable as possible.

Follow up

Once your blood calcium levels go back to normal, your doctor will want to keep a close eye on you. You will have regular blood and urine tests to make sure the treatment is still working.

It is very important that you see your doctor as soon as possible if you feel the symptoms of high calcium are coming back. Even if something else is causing your symptoms, it is better to see your doctor to find out for sure.

You might worry about eating foods that contain calcium if you have high calcium or think you may be at risk of it. But cutting down on these foods will not help high calcium that is caused by cancer. It will not make any difference to your calcium levels.

Do talk to your doctor or nurse if you are concerned about your diet. Make sure you check with your doctor before taking any vitamin or mineral supplements.

  • Hypercalcaemia of malignancy

    BMJ Best Practice 2021

  • Calcium imbalance

    BNF 2021

  • ESMO Handbook of Oncological Emergencies (2nd edition)

    ESMO Press, 2016

  • The Clinical Management of Cancer-Related Hypercalcaemia

    R McDonald and others

    Cheshire and Merseyside Palliative and End of Life Care Strategic Clinical Network Standards and Guidelines 2018

  • Cancer-Related Hypercalcemia

    W Goldner

    Journal of Oncology Practice,2016

    Volume 12, Number 5

  • Cancer and its management (7th edition)

    J Tobias and D Hochhauser

    Wiley-Blackwell, 2015

Last reviewed: 
28 Jan 2022
Next review due: 
28 Jan 2025

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