Most recent findings in the field have confirmed that there is no safe level of exposure to cigarette smoke - just a single puff can block your arteries and trigger a heart attack.
The 700-page the US Surgeon General's report has found there was no safe level of exposure to cigarette smoke-whether you deliberately inhale or breathe it in second hand.
"That one puff on that cigarette could be the one that causes your heart attack," the Daily Mail quoted Surgeon General Regina Benjamin, as saying.
Smoke immediately seeps into the bloodstream and changes its chemistry so that it becomes stickier, allowing clots to form that can squeeze shut already narrowed arteries.
This is in addition to the more subtle long-term damage to blood vessels themselves, making them narrower.
Terry Pechacek of the Centers for Disease Control and Prevention said this meant smoking a cigarette at a party could be enough to trigger a heart attack in someone whose arteries are silently clogged.Too often people think the occasional social cigarette is not so dangerous, when in fact this report says yes, it is," he said.
The report also found even brief exposure to second-hand smoke "could trigger acute cardiac events such as heart attack."
The report also included the latest genetic findings to help explain why some people become more addicted and develop associated diseases quicker than others.