Nicotine
The primary reason smokers continue to smoke is addiction. Cigarettes contain nicotine, a highly addictive substance found naturally in tobacco. It travels quickly to the brain when it is inhaled, causing a feeling of relaxation. The relaxing effects from nicotine are temporary. When the body rids itself of nicotine, it experiences withdrawal and craves another cigarette. Creating a cycle of dependency. Nicotine withdrawal symptoms include:
Cravings
Anxiety
Moodiness
Irritability
Inattentiveness