Smoking can cause many diseases. In fact, smoking itself is a disease called tobacco dependence, which is essentially nicotine dependence, addiction. Habitual psychological or physical dependence on a substance or behavior that cannot be consciously controlled is addiction. Tobacco users are nicotine dependent, characterized by an uncontrollable urge to seek nicotine, as well as the compulsive and continuous use of nicotine in order to experience the euphoria and pleasure it brings, and to avoid possible withdrawal symptoms (the discomfort and pain that comes with not smoking). Therefore, smoking is not a habit but a disease. As early as 1998, the World Health Organization included smoking, or more precisely tobacco dependence, as a disease in the International Classification of Diseases.