How Smoking Affects Your Looks & Life Slideshow Tips to Quit Smoking Slideshow Take the Quiz on Smoking Tobacco: A South American herb (Nicotiana tabacum) whose leaves contain 2 to 8 percent nicotine and serve as the source of both smoking and smokeless tobacco and the basis of great health hazards. From Smoking Cessation Resources Natural Ways to Whiten Your TeethHow Smoking Could Affect Your EarsAre You Ready to Quit Smoking? Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? Therapy at Home?