Severe heart failure can cause the lungs to fill with fluid, leaving people feeling like they are drowning, says a new campaign by the British Heart Foundation.
But a BHF survey suggests that 80% of adults are unaware of its impact on everyday life.
There is no cure for heart failure, which can lead to extreme exhaustion and breathlessness.
Experts say stem cell research could be the key to repairing damaged hearts.
More than 750,000 people in the UK currently live with heart failure, which means that the heart is not pumping blood around the body as well as it used to. It is commonly caused by a heart attack.
While patients with mild heart failure can live a relatively normal life with the help of drugs, those with severe heart failure can suffer prolonged pain and distress because everyday tasks such as having a shower or doing the shopping require enormous amounts of energy and leave them exhausted.
Past UK research suggests that around 28% of all heart failure patients face a daily struggle as a result of permanent damage to the heart muscle.
However, the survey of 2,170 adults by the British Heart Foundation suggests that more than three-quarters of respondents are unaware of the effects of severe heart failure on people's lives.
More than a third of those surveyed thought that heart failure meant that the heart stopped working altogether and 33% wrongly believed the heart could repair itself.
Dr Mike Knapton, associate medical director at the BHF, say more and more people are surviving heart attacks due to advances in medicine but this creates its own problem.
"People with acute, severe heart failure have a worse prognosis than most cancers. Heart failure has a very significant effect on morbidity. It can be disabling, it can leave people breathless and they can end up chair-bound and bed-bound."
The priority now, he says, is to find out how to repair damage to the heart with the help of the BHF's Mending Broken Hearts Appeal.
"The human heart cell is not able to regenerate, unlike the liver, and we want to understand why in order to improve new treatments for the future.
"We aim to raise money to carry out basic research into regenerative medicine. Stem cells could help by offering therapeutic interventions."
He added that it was possible that a cure for heart failure could be achieved within 10 to 15 years.