People living with high blood pressure and blood cholesterol have been warned not to be complacent about dealing with the conditions, to avoid heart disease.

Australians are being urged not to be complacent about high blood pressure and elevated cholesterol if they don't want to die of heart disease.

The grim warning comes as research shows the vast majority of Australians with the two conditions don't know they have an increased risk of experiencing heart issues such as a cardiac arrest or stroke.

The Heart Foundation says only 11 per cent of people with high cholesterol realise they are at a higher risk of heart disease.

Only eight per cent of people living with high blood pressure are aware they are at an increased risk - despite high blood pressure being responsible for one in two deaths from heart disease.

The Heart Foundation is hoping to boost awareness of heart disease risks posed by the conditions to mark World Heart Day on Sunday.

"These are risk factors that can be managed if people modify their lifestyles and take appropriate medications," the foundation's national chief executive John Kelly said.

"Complacency can be a killer when it comes to your heart ... now is the time to promise to make changes before it's too late."

Heart disease is responsible for more than 17,000 deaths across Australia each year, and costs the economy about $6.76 billion.

People interested in better understanding their heart disease risks are being encouraged to use a tool on the foundation's website, which determines how their "heart age" compares to their actual age.

It does so by comparing their risk of having a heart attack or stroke to others their age, taking into account their own specific risk factors.