Erectile dysfunction may be a warning sign of a heart disease or other conditons.

Recent studies have linked erectile dysfunction and heart disease and that men with heart disease and erectile dysfunction were twice as likely to die earlier than men who have heart disease alone.

In a report published online in the Journal of Sexual Medicine, it was reported that researchers found 2,200 deaths in the U.S. that were linked to erectile dysfunction drugs from 2000 to 2010.

But the number is not cause for immediate concern, given the number of men estimated to be taking the drugs, which is between 15 million and 84 million men in the U.S., according to the study.

Rather, researchers say, the findings highlight the fact that erectile dysfunction may be a warning sign of heart or other conditions a patient is not yet aware of but should be concerned about.

"These are very safe medications," said study author Dr. Gregory Lowe, a urologist at Ohio State University Medical Center.

Dr. Graham Jackson, a cardiologist at St. Thomas Hospital in London and one of the authors of the Princeton consensus, a set of guidelines for heart patients when dealing with sexual activity and erectile dysfunction, advised men over 30 years to have a cardiac risk assessment.

Last year, an updated guidelines recommending specific lines of cardiac screening for men with erectile dysfunction wasco-authored by Jackson. He also gave physicians guidance on the use of medications such as Viagra, Cialis and Levitra that are usually given to erectile dysfunction patients.

The researchers said that patients should be aware of potential hazards from erectile dysfunction as they might be taking counterfeit drugs.

"I do think it's important for patients to consult their physicians, and not obtain these medications through the Internet,or some other source,"Lowe said.