Emergency services are urging more Australians to learn life-saving techniques such as CPR and how to use a defibrillator, as they mark World First Aid Day.

Australia has one of the lowest rates of first aid training in the world and emergency services want more people to learn how to save a life.

Less than five per cent of people are equipped to handle an emergency situation, according to a 2017 Red Cross study.

With the coronavirus pandemic gripping the nation, St John Ambulance NSW chief executive officer Sarah Lance says there's never been a more important time to learn first aid.

"We know that GP clinics across the country have reported major drops in patient numbers due to the pandemic, either because of COVID-19 fears or problems transitioning to telehealth services," Ms Lance said in a statement.

"Everyone in the community should know how to respond to a first-aid emergency, but also be able recognise when you need to seek medical help - whether that's calling an ambulance or visiting a GP."

Australians are delaying treatment when experiencing symptoms of a sudden cardiac arrest - a condition that causes unexpected loss of heart function, breathing and consciousness.

Ms Lance says more than 30,000 people experience an out-of-hospital cardiac arrest in Australia every year, with a survival rate of less than nine per cent.

The combination of CPR and defibrillation is the only definitive treatment for sudden cardiac arrest, increasing survival rates by up to 70 per cent.

"With hundreds of defibrillators installed in public spaces, it is now more important than ever to know how to use them," she said.

World First Aid Day is a reminder for people to enrol in a first aid training course, or update any previously completed training.

Australian Associated Press