For non-smokers, it simply blows their minds when they see someone having a major craving for nicotine. You know -- agitated, irritable and completely focused on just one thing -- getting their next fix of nicotine. Nope, non-smokers just don't get it. But smokers do. And it's called addiction. Some of it is psychological… some of it is physical, but it all comes down to one thing: the addictive nature of nicotine. And make no doubt, the tobacco companies are banking on just that. So how does it work? Here's how:

• When nicotine enters the body, it becomes paired with the event or action happening at the time: studying, socializing, drinking coffee, etc. Therefore, when this same event or environment is encountered again, the brain triggers a craving for nicotine.
  
  
• Psychological habits can also be formed that are related to smoking. For example, smokers become accustomed to having something to do with their hands or mouth when they smoke, as well as the physical act of inhaling and exhaling the smoke. Simply put, when these habits are gone, they miss them.
  
  
• Scientists have also found a genetic explanation for nicotine addiction. People who smoke and have family members who are addicted are more likely to become addicted themselves, even if they begin as occasional smokers.
  
  
• The more an individual smokes, the more the brain adapts and changes itself to create more receptors in its nerve endings to take in the nicotine. By increasing the number of receptors, the person begins to need more and more nicotine to feel normal. This process is called up-regulation.

Here are some ways to spot someone with a bonafide nicotine addiction:

• They crave cigarettes.
• They smoke without thinking about it.
• They rationalize or justify smoking.
• They choose friends, jobs or activities that permit them to smoke.
• They avoid those that do not.
• They continue using despite good reasons for quitting.

The Fagerstrom Questionnaire is a good resource to measure a person’s level of nicotine addiction.