High blood pressure is a silent killer, and an alarming one in five Cambodians die from cardio-vascular disease as a result of it.

Many people don’t realise they have high blood pressure, because it has no symptoms or warning signs.

Raised blood pressure – known medically as hypertension – is a risk factor in heart disease, strokes, kidney failure and blindness.

Fortunately, it’s easy to detect and treat. The best way to know whether you have high blood pressure is to have it checked: it’s that simple.

The overall goal for this year’s World Health Day, which fell yesterday, is to reduce the number of heart attacks and strokes.

Although the precise causes of hypertension are mostly unknown, several factors have been associated with the condition.

They include smoking, high levels of alcohol consumption, obesity, diabetes, a sedentary lifestyle, lack of physical activity and high levels of salt intake (sodium sensitivity).

Globalisation has brought processed foods and diets high in total energy, fats, salt and sugar into the homes of Cambodians.

Between 2003 and 2008, imports of soft drinks and candy rose by more than 5,000 per cent and 24,000 per cent respectively.

According to a 2010 nation-wide survey on chronic disease risk factors, about 675,000 Cambodians, or 11 per cent of the population aged between 25 and 64, have high blood pressure.

The survey found that in urban areas, the prevalence of high blood pressure was about 17 per cent. In rural areas, it was 10 per cent.

More than 80 per cent of those with high blood pressure were not being treated for it, and were diagnosed only because they participated in the survey.

A big risk factor for many Cam-bodians is their high intake of salt. Too much salt can raise blood pressure, increasing the risk of health problems, especially cardio-vascular disease.

A body in good health adjusts to a temporarily higher intake of dietary salt, but with age this natural regulation becomes less effective.

In this situation, high salt intake may increase blood pressure, bringing a higher risk of heart disease and blood-vessel damage.

The WHO recommends that daily salt intake not exceed five grams, or less than one full teaspoon.

It’s estimated that a daily salt intake of five grams or less would reduce the incidence of strokes by 23 per cent and cardio-vascular disease by 17 per cent, averting 1.25 million strokes and almost three million heart-related problems globally each year.

Preliminary analysis of a salt intake survey in one Phnom Penh community reveals that 70 per cent of adults have a salt intake higher than five grams a day.

The average salt intake of adult Cambodians is seven grams a day, and the highest percentile of adult salt intake is an alarming 24 grams.

This is a ticking public-health time bomb, made more lethal by diets high in saturated fats, low consumption of fruit and veget-ables, lack of physical activity, smoking and harmful use of alcohol.

Globalisation, coupled with demographic and social changes, has resulted in a dual burden of infectious and non-communicable diseases in a health-care system that is under-resourced.

High blood pressure is also one of the risk factors for development of non-communicable diseases.

To stall this epidemic, the WHO has developed technical guidelines such as the Framework Convention on Tobacco Control, the Global Strategy on Diet, Physical Activity and Health and the Action Plan for the Prevention and Control of Non-communicable Diseases.

This action plan, together with regional plans for prevention and control of non-communicable diseases, offers member countries guidance on national strategies.

World Health Day 2013 is to raise awareness of the causes and consequences of high blood pressure; provide information on how to prevent high blood pressure and related complications; encourage adults to check their blood pressure and follow the advice of health-care professionals; encourage self-care to prevent high blood pressure; make blood-pressure measurement affordable to all; and incite national and local authorities to create enabling environments for healthy behaviour.

The WHO is committed to supp-orting the Royal Government’s efforts in fighting hypertension.

Most of the risk factors for high blood pressure, and the preventive and control measures, lie outside the health sector and strongly require collaborative efforts with sectors such as agriculture, education, information, public transport, trade, urban planning, finance, local government and private sectors, especially the food industry.

A national, multi-sector action plan for the prevention and control of non-communicable diseases, and a coordination mechanism to implement this action plan, must be developed with support from

the international community.

With government ministries, UN agencies, NGOs and development partners joining hands, World Health Day 2013 can be the first step towards a healthy Cambodian society.

Dr Pieter JM Van Maaren is the World Health Organisation’s representative in Cambodia.