"It used to be the other way around, where people with heart problems had ED. Now, we're learning that ED is a warning for more serious diseases."

ED is an early manifestation of the blood vessel damage caused by high blood pressure, diabetes and other heart disease risk factors.

"ED is the centre of a lot of diseases. If you have it, you must check for all other vascular diseases, including prostrate problems. It's a common mechanism, treating one will treat them all.

"People used to worry that if you have a heart problem, you should not take Viagra, but that's not true. These people were not healthy enough to be having sex in the first place."

Dr Ng says a good self-test to see if you're healthy enough to have sexual intercourse is if you can climb two flights of stairs in 20 seconds.

If you can't, you should see a doctor immediately as this could indicate serious problems.

"Many people think it's as simple as popping a pill and solving all your problems.

"But ED is an early warning sign. If the warning sign is ignored, you could have a heart attack or a stroke.

"Some ED cases are all in the mind. They're caused by psychological problems, but a majority of ED patients are not 'clean' in other areas of their health."

He calls for wives to push their husbands to see a doctor as soon as they notice an ED problem.

"If your husband suffers from ED, you could save his life by making him see a doctor.

"But not just any doctor. It's important to see a medical practitioner that will not only push pills to you, but counsel you and look at your overall health."

Many men, he says, suffer for years with ED before being egged on by their wives to seek help.

Dr Ng does, however, warns against counterfeit magic blue pills.

"Viagra is the most bootlegged drug out there. People are giving it away over the counter and selling it in markets."

He says the public should not self-prescribe medication, much less buy them from dodgy places.

This story was first published in the New Straits Times on Sept 21, 2008.