People in Hong Kong should learn more about "good cholesterol" and take appropriate action, said the Hong Kong Atherosclerosis Society (HKAS).

While many people are aware how high level of cholesterol can cause serious health problems, few understand the difference between "good" cholesterol and "bad" cholesterol.

The former carries excessive cholesterol back to the liver and discharge them from the body, while the latter carries cholesterol back to every part of the body, leading to atherosclerosis. But if good cholesterol is below standard, a person can suffer high risks of cardiovascular diseases, even if the total cholesterol level is not high enough to signal any sign, the HKAS said.

The failure to meet good cholesterol standard is a matter of great concern in Hong Kong. According to a study conducted in 2005, 26 per cent male and 8 per cent participants failed to meet the standard.

There is poor awareness of the subject, since most local clinics and laboratories offer only total cholesterol testing, without any further explanations to the test-takers.

"Most Western countries have come to distinguish good cholesterol from bad cholesterol in the body check-ups they offer, but Hong Kong is still lagging behind in this area," said Leung Tat-chi from HKAS.

Norman Chan from HKAS also questioned the reliability of the tests at most private clinics and laboratories, as they are not currently regulated by laws and the tests may not be supervised by doctors.

"There're cases in which we compared the test results with the ones we obtained from a laboratory at the university or hospital, and found notable differences," Chan said.

As atherosclerosis shows no symptoms in its early stages, regular check-up is essential for prevention of the disease. As the testing of good and bad cholesterol is conducted with the same blood sample, it should not cause extra troubles or costs for the client.

"The only difference is that at a reliable clinic, there will be testing on the thickness of your arteries as well," Chan said. "It takes an hour to complete the test and receive the report and only costs about HK$200 at most places," Chan said.

While people aged 45 or above should have annual check-ups, youths who show signs of obesity should be careful about their good cholesterol level, since it can be related to atherosclerosis, Chan said.