Why should I quit smoking?

Because it could save your life. They don't call cigarettes "cancer sticks" and "coffin nails" for nothing. When you smoke, you're exposing yourself to more than 4,000 chemicals, including cyanide, benzene, and ammonia -- and at least 40 of those chemicals can cause cancer. Perhaps the best known is nicotine, an addictive compound that can make it ferociously hard to stop smoking.