You may have heard that smoking is one of the most difficult addictions to overcome, and the majority of people who have successfully done it would probably agree. In fact, it has been said that quitting smoking is even more difficult than overcoming addictions to illegal drugs like heroin and cocaine. Why is that?

One of the reasons may be that smoking is for the most part a socially acceptable habit (though this is acceptance level is declining steadily), but there are also other reasons why smoking is such a powerfully addictive habit.

1) Physical addiction.

Nicotine is a powerful drug that acts directly upon receptors in your brain. These receptors are stimulated by nicotine, resulting in several different physiological responses such as elevated heart rate, blood pressure and respiration, and increased mental alertness, among others. The longer you ingest nicotine, the more of these receptors you develop. Over time, these receptors become less sensitive to nicotine and begin to require increased doses to achieve the same level of stimulation. When you try to stop smoking, feelings of intense discomfort (known as withdrawal) will occur.

People have described nicotine withdrawal symptoms as "demons" or "torture" because they are so strong. Most people report feelings of intense restlessness, irritability, fatigue, dizziness, and even flu-like symptoms or chest pain.

Physical withdrawal symptoms can often be eased with the use of nicotine replacement products like gum, patches and lozenges, but many people feel that these products only delay the inevitable by keeping the ex-smoker hooked on nicotine. Still other people claim that using nicotine replacement products helped them conquer one aspect of quitting at a time - for example, the psychological or emotional repercussions, before tackling the physical addiction.

2) Emotional addiction.

The emotional connection to smoking can easily be as strong as physical dependence upon nicotine. There are a variety of reasons why people smoke, but one of the most common reasons that develops over time is an emotional "crutch" or "cover".

Many smokers report using smoking as a coping mechanism for feelings like anger, frustration, boredom, stress and sadness that they don't know how to deal with otherwise. Rather than processing their emotions, they reach for a cigarette (or cigar, pipe, etc.) and distract themselves from it.

Of course, this doesn't really help them deal with unpleasant feelings, but they believe it does. When the smoker tries to quit smoking, they suddenly find themselves overwhelmed with difficult emotions and no way to handle them.

One of the most effective ways to handle these errant emotions is to find alternative ways to process them when they come up. Journaling, venting to a friend, exercise, meditation and affirmations are often helpful. The important thing is not to bottle up your emotions and avoid them, because they just keep coming back until they are fully processed and released.

3) Psychological addiction.

Still another powerful connection to smoking results from the physical act itself: psychological dependence. Since most smokers smoke many times in a day for years at a time, they get very comfortable with the act of smoking, always having a cigarette, cigar or pipe in their hand and mouth. Even if a person is successful in reducing physical cravings and dealing with their emotions, they still may struggle with a sense of loss or aimlessness. The activity that used to occupy so much of their time and attention every day is now gone and they don't quite know what to do with themselves.

One good way to conquer this type of dependence is to change your smoking routine in the weeks leading up to your quit date. For example, if you tend to smoke while driving, talking on the phone or watching television, gradually reduce your smoking habit during those activities. Smoke in locations where you normally wouldn't, like standing outside. When you finally do quit for good, you'll have an easier time engaging in your normal activities without missing the act of smoking so much.