Three quarters of Britons have little or no knowledge about key health indicators that could help save their lives, according to new research.

Vital statistics such as Body Mass Index (BMI), cholesterol levels and blood pressure are used to monitor health and predict likelihood of heart disease but 33 million Brits admit their ignorance of these facts, warns private medical insurer PruHealth.

Figures from PruHealth found only a quarter of people know their BMT and 60 per cent do not even know what it stands for, less than half of Brits know their blood pressure measurement and only 29 per cent know their cholesterol level.

The government has launched the 'small changes make a big difference' campaign with free fitness assessments and discounted health screening to try and help encourage consumers to make small changes to their lifestyle to make a big difference to their health.

"Having a vague understanding of your height and weight, and thinking you need to lose a few pounds is simply not enough to keep healthy," warned Dr Chris Dark from PruHealth.

"Instead you need to know your Vital Stats and review them regularly. It's worth it because in the long run, it could help reduce and prevent future problems and, ultimately, save your life."

Dr Dark added: "Even for those who do exercise regularly, keep active and eat healthily, it's still important to know your Vital Stats as they can help point out 'lifestyle' factors you can work on to reduce your risk of heart disease."