The elevated levels of cholesterol in the body can be a silent killer without showing symptoms for prolonged periods, said a medical expert.

Therefore, everyone aged 20 and above should have their cholesterol level measured and checked at least once in every five years, said Consultant Cardiologist of Sime Darby Medical Centre Subang Jaya, Dr Jeyamalar Rajadurai.

"Most people with high cholesterol do not have any symptoms, so many are unaware that their cholesterol is too high.

"A blood test is performed to check levels of cholesterol in the blood," she said during an interactive forum 'Key Challenges of Managing High Cholesterol for High Risk Patients' by MSD (known as MErck & Co, in US and Canada) here, Wednesday.

She explained that such elevated levels, known as Hypercholesterolemia in medical sciences, may be due to heritance, overproduction of cholesterol in the liver of the group having low efficiency in removing bad cholesterol from the blood.

"Behaviours that increase the risk of Hypercholesterolemia include unhealthy diet, physical inactivity, obesity and genetics.

"According to medical studies, being a genetic condition, cholesterol can be inherited and as such, children with familial history need to start routine check-ups from as early as the age of five.

"About one out of every 500 people has this inherited disorder called familia hypercholesterolemia, which can cause extremely high cholesterol levels," she said.

Meanwhile, senior consultant cardiologist Dr David Quek said recommended lifestyle change for those with Hypercholesterolemia include giving up smoking, limiting alcohol consumption, increasing physical activity and maintaining a healthy weight.

"On average, diet and exercise can reduce bad cholesterol by about 10 percent in our body while medications can lower bad cholesterol by another 20 per cent to more than 50 per cent," he said.

He said unchecked Hypercholesterolemia in individuals could lead to the formation of plaques in the arteries, which could further lead to eruptions of the plaque in the vessels.

"These eruptions can be associated with bleeding and formation of blood clots in those areas.

"From here, the clots can further be released into the blood vessels in a solid mass that can block the flow of blood to major organs via the artery. That's how heart attack and stroke happened to them," he said.

Dr Jeyamalar said Hypercholesterolemia could not be cured but the risk to get a heart attack and stroke could be reduced by taking medicines.

"To help reduce bad cholesterol in the blood, doctors could prescribe single medication or a combination of medications. Among the major drug classes that reduce blood cholesterol include statins, fibrates, resins, niacin and cholesterol absorption inhibitors.

“However, once a patient is diagnosed to be suffering from Hypercholesterolemia, he or she must take medicine on time," she said.

She said globally, a third of ischemic heart disease was attributable to high cholesterol, which was estimated to cause 2.6 million deaths and 29.7 million disability adjusted life years.

"Ischemic heart disease remained the principle cause of death in Malaysia for the past 10 years.

"The Department of Statistics Malaysia's report showed that the number of deaths due to Ischemic heart disease in 2014 was the highest at 13.5 per cent," she said.

-- BERNAMA