Many adults in the UK are unaware of the risk factors for heart disease, according to a new poll.
While a third of people are worried about getting dementia or cancer, only 2% are afraid of coronary heart disease, a survey by the British Heart Foundation has found.
And one in ten adults confessed to not knowing how to look after their hearts.
Coronary heart disease (CHD) is responsible for about 74,000 deaths in the UK each year.
About one in five men and one in eight women die from the condition.
Dr Mike Knapton, associate medical director at the British Heart Foundation, said: "Your heart is the most vital organ in the body, but all too often we take it for granted.
"Despite being a largely preventable condition, coronary heart disease is still the UK's single biggest killer, causing unnecessary heartache for thousands of families."
As well as chest pain, the main symptoms of CHD are heart attacks and heart failure.
However, not everyone has the same symptoms and some people may not have any before CHD is diagnosed.
Risk factors include smoking, high cholesterol, high blood pressure and diabetes.
Gail Sullivan, from Oxted in Surrey, lost her son Daniel to the disease.
"At his age - 43 - he shouldn't have died the way he did and I am very passionate about trying to get this awareness across," she said.
"I don't want him to have died in vain. It's devastated the whole family. We didn't know there was anything wrong. There was no sign that he was ill whatsoever."
She said the call informing her that Daniel had had a heart attack remained "etched in my mind".
At the hospital she discovered he had collapsed at work with a cardiac arrest.
"They got his heart started, got him into the ambulance where he had another cardiac arrest, and then got him to the hospital and he had another cardiac arrest," she said.
"They got his heart started again and he was on life support for a couple of weeks.
"But they told us that his brain had died, and when they took away the machines he passed away on the Friday."
The doctors said that smoking, high blood pressure and high cholesterol had affected the health of Daniel's heart.
"When they say the silent killer, I now know what they mean," she said. "There were no signs of that. You wouldn't look at him and say, 'Oh gosh, Dan, you look really ill'. You would never have been able to tell."
The British Heart Foundation has issued 10 tips to prevent heart disease:
- Give up smoking
- If you're over 40, take up your free NHS health check
- Maintain a healthy weight
- Lead an active lifestyle
- Ditch the salt
- Eat your "five a day" of fruit and vegetables
- Cut down on saturated fat
- Read food labels to find out if something is healthy for you
- Don't drink too much alcohol
- Watch food portion sizes.
The poll was conducted by YouGov and included 1,010 men and 1,089 women.
Meanwhile the World Health Organization (WHO) is calling on countries to take action on salt to cut deaths from heart disease. It wants governments to sign up to reducing global salt intake.
"If the target to reduce salt by 30% globally by 2025 is achieved, millions of lives can be saved from heart disease, stroke and related conditions," said director Dr Oleg Chestnov.