The heart

Some people with cancer may have problems with their heart. You may have been told that your cancer treatment can affect your heart, or you might already have a heart condition.

The heart is a large muscle. It pumps blood around your body to deliver oxygen and nutrients, and to remove carbon dioxide and waste products.

Blood that is low in oxygen returns to the heart from the body. It is then pumped into the lungs, where oxygen passes into the blood. The blood then returns to the heart and the heart pumps this oxygen-rich blood around the body.

The heart has blood vessels that carry blood to the heart. These are the coronary arteries. It also has its own electrical supply which keeps it beating normally.

An unhealthy heart may not be able to pump blood around the body as efficiently. You might feel breathless or tired and may not be able to do the things you enjoy. An unhealthy heart can also mean that you have an increased risk of developing other heart problems after cancer treatment.

The heart and cancer

Some people affected by cancer have problems with their heart health. This is because some cancer treatments can affect the heart. Problems can also arise if you already have a heart condition when you’re diagnosed with cancer. The information in this section is for you if:

  • you’ve been told that your cancer treatment may affect your heart
  • you have a heart condition and need cancer treatment
  • you’d like to find out how you can improve the health of your heart before, during and after cancer treatment.


About the heart

The heart is a large muscle that pumps blood around your body. The blood delivers oxygen and nutrients around your body and carries away carbon dioxide and waste products.

The heart is divided into four chambers. There are two collecting chambers where blood goes into the heart. These are called the right and left atria. There are also two pumping chambers that pump blood out of the heart. These are called the right and left ventricles.

There are also four valves inside the heart. These make sure the blood travels in one direction through the chambers of the heart.

The heart
The heart

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Key

Pulmonary arteries – carry blood low in oxygen from the heart to the lungs.

Pulmonary veins – carry blood rich in oxygen from the lungs to the heart.

Aorta – carries blood rich in oxygen from the heart to the body.

Coronary arteries – carry blood rich in oxygen to the heart muscle.

Superior vena cava – carries blood low in oxygen from the upper part of the body to the heart.

Inferior vena cava – carries blood low in oxygen from the lower part of the body to the heart.


How the heart works

Blood that is low in oxygen returns to the heart from the body in the veins. It enters the right atrium of the heart. From the right atrium, it passes into the right ventricle. It is then pumped into the blood vessels that go to the lungs. In the lungs, oxygen (which is breathed in) passes into the blood. The blood then returns to the left atrium of the heart. From the left atrium, the oxygen-rich blood passes into the left ventricle. This pumps blood to the whole body through the arteries.

The direction that blood flows around the body
The direction that blood flows around the body

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The heart also needs its own supply of oxygen-rich blood to help it work. It has a network of blood vessels called the coronary arteries, which delivers the oxygen it needs. The heart also has its own electrical supply to keep it beating normally.

The British Heart Foundation has an interactive online learning tool. It uses film, interactive tasks and quizzes to show how a healthy heart works.


Why is a healthy heart important?

If your heart isn’t healthy, it may gradually be less able to pump blood around your body as well as it should. This can lead to symptoms such as breathlessness and fatigue, which can stop you from doing the things you enjoy.

Having an unhealthy heart may also increase your risk of developing other heart problems as a side effect of surgery or other cancer treatments. People with healthy hearts are less likely to develop heart problems due to cancer treatments.


Working together to create information for you

We worked with British Heart Foundation to write our content on heart health.

Thank you to all of the people affected by cancer who reviewed what you're reading and have helped our information to develop.

You could help us too when you join our Cancer Voices Network.

Back to Looking after your heart

Heart disease

Different parts of the heart can become diseased or damaged. Each condition will cause different symptoms.

Risk factors and your heart

Some factors can increase your risk of developing heart problems. Improving your lifestyle can lower your risk.

Keeping your heart healthy

You can help keep your heart healthy by eating well, keeping active, controlling stress and giving up smoking.

Top ten tips for heart health

Try following these 10 tips to keep your heart healthy. You can try these before, during and after cancer treatment.