A 30-year follow of over 101,000 women in the Nurses' Health Study found that even smoking a few as 1-14 cigarettes per day almost doubled the risk for sudden cardiac death, compared to non-smokers. Those who smoked 25+ cigarettes per day showed a 3.3 fold increased risk. However, 15-20 years after quitting, former smokers declined to the risk of those who had never smoked.
PositiveTip: The benefits of quitting smoking are measurable and significant.