Singapore will not be adopting the new, stricter high blood pressure definition of 130/80 that the American Heart Association (AHA) has recommended.

It will continue to use the current 140/90 to indicate hypertension. This is the value also used in Europe and Australia, a Ministry of Health (MOH) spokesman said.

She added: "Essentially, while these new guidelines change the definition of hypertension for US patients, they do not change the approach to management in a major way."

This is because despite the new cut-off, about 80 per cent of the newly defined hypertensives in the United States will not require any medication, only lifestyle changes.

Based on the new definition, 46 per cent of Americans are now considered to be suffering from high blood pressure, up from 36 per cent.

The spokesman said MOH will continue to review the evidence of the new AHA guidelines and how they apply to the local population.

She added: "Blood pressure can be kept in the healthy range by living a healthy lifestyle such as having a balanced diet, avoiding excess salt intake, having regular physical activity and not smoking."

Dr Chin Chee Tang, a senior cardiologist at the National Heart Centre Singapore, said doctors have always known that the effects of blood pressure on health are a continuum, so thresholds for "normal" or "not normal" are not always useful.

Dr Chin said: "The lower the blood pressure is, the lower the risk of adverse outcomes. This has to be tempered with the increased risk of potential side-effects of treatment."

He said the main advantage of the new US cut-off is it could "increase awareness of the dangers associated with high blood pressure, and hence an earlier drive for individuals to optimise their blood pressure".

But the downside of a lower threshold includes implications for insurance coverage. It would also affect future research and treatments by making comparisons more difficult, he said.

Dr Chia Shi Lu, head of the Government Parliamentary Committee for Health, said "there is no reason for us or other countries to adopt that standard as yet" because it is very much like the debate over the cut-off point for diabetes or cholesterol levels.

These are all continuums, and a person does not suddenly tip over from being healthy to unhealthy at a particular point.

Dr Chia said: "If we change, suddenly, we will have many more people classified as hypertensive, and this may result in unnecessary treatment for many."

Like Dr Chin, he said it might also affect health insurance coverage, such as an increase in premiums to cover the additional risk, "which may in fact be very little".

The ministry has taken the right approach, said Dr Chia, an orthopaedic surgeon at Singapore General Hospital. He added: "There is no solid basis for saying now that a systolic pressure of 130 is significantly riskier."

The 2010 National Health Survey found that 23.5 per cent of people in Singapore are hypertensive, with one in four not being aware of it.

More than half the people aged 60 years and older have high blood pressure.

According to the World Health Organisation, raised blood pressure is responsible for 7.5 million deaths a year, or almost 13 per cent of all deaths.

It is a major risk factor for heart diseases and stroke. People who are obese or diabetic are more likely to have hypertension.