Heart failure means that the heart is unable to pump blood around the body properly. It usually occurs because the heart has become too weak or stiff.

It's sometimes called congestive heart failure, although this name isn't widely used nowadays.
Heart failure doesn't mean your heart has stopped working. It just needs some support to help it work better.
It can occur at any age, but is most common in older people.
Heart failure is a long-term condition that tends to get gradually worse over time.
It can't usually be cured, but the symptoms can often be controlled for many years.