Tobacco is a plant whose leaves are dried and used in products that are smoked, chewed, or sniffed, such as cigarettes, cigars, chewing tobacco, and snuff. Nicotine is the addictive chemical in tobacco. Smoking tobacco causes numerous health issues, including cancer, lung disease, heart disease, and stroke. Secondhand smoke can also significantly impact health, resulting in diseases and increased infant death. Quitting tobacco is difficult due to nicotine addiction and withdrawal symptoms. Various nicotine replacement therapies and medications can help in quitting. While tobacco use among youth has declined in the US in recent decades, it remains a serious public health issue.