Tobacco use increases the risk of many types of cancers and heart disease. Among adults who use tobacco, the vast majority began using before age 18. Adolescents believe they will be able to quit smoking at any point and underestimate the addictive nature of tobacco use. Preventing the use of tobacco among adolescents can help to reduce the short-term health effects of smoking such as depression and anxiety as well as long-term health effects such as cancer and heart disease. Schools are crucial to tobacco prevention by fostering a culture of prevention and an environment where tobacco is not tolerated.