Cigarette

More than 7 million Deaths every year.

The tobacco epidemic is one of the biggest public health threats the world has ever faced, killing more than 7 million people a year. More than 6 million of those deaths are the result of direct tobacco use while around 890 000 are the result of non-smokers being exposed to second-hand smoke.
Around 80% of the 1.1 billion smokers worldwide live in low- and middle-income countries, where the burden of tobacco-related illness and death is heaviest. Tobacco users who die prematurely deprive their families of income, raise the cost of health care and hinder economic development.
In some countries, children from poor households are frequently employed in tobacco farming to provide family income. These children are especially vulnerable to "green tobacco sickness", which is caused by the nicotine that is absorbed through the skin from the handling of wet tobacco leaves
 

Heart

Smoking damages your heart and your blood circulation, increasing the risk of conditions such as coronary heart disease, heart attack, stroke, peripheral vascular disease (damaged blood vessels) and cerebrovascular disease (damaged arteries that supply blood to your brain).
Carbon monoxide from the smoke and nicotine both put a strain on the heart by making it work faster. They also increase your risk of blood clots. Other chemicals in cigarette smoke damage the lining of your coronary arteries, leading to furring of the arteries.
In fact, smoking doubles your risk of having a heart attack, and if you smoke you have twice the risk of dying from coronary heart disease than lifetime non-smokers.
The good news is that after only one year of not smoking, your risk is reduced by half. After stopping for 15 years, your risk is similar to that of someone who has never smoked.