Understanding why you smoke can be very useful for your quitting plan. There are various factors that contribute to your urge to smoke, but every smoker has different reasons for lighting up. By identifying your main reason, you can better focus your efforts to fight these urges.

1. Chemical addiction to nicotine

Nicotine is the chemically addictive substance found in tobacco. If you can't last half a day without smoking, if you need a cigarette as soon as you wake up in the morning, or if you feel so fatigued when you don't smoke, you're probably addicted to the nicotine in cigarettes.

Being hooked on nicotine is a form of drug addiction: Nicotine is a powerful drug which acts on the brain and other organs. When inhaled, nicotine in the smoke enters the bloodstream through the lungs, and can reach the brain within 7 to 10 seconds. Nicotine produces those pleasant feelings that get you hooked, such as reduced tension and increased focus, but it also does everything from narrowing your arteries to raising your blood pressure to interfering with your hormones.

And as with all addictive substances, nicotine produces unpleasant withdrawl symptoms including irritability and fatigue once you stop smoking, which is one reason why smoking is so hard to quit.

Quit Plan: If you are addicted to nicotine in the cigarettes, nicotine replacement therapies may be helpful. These smoking-cessation aids contain nicotine to help wean you off your addiction and minimize withdrawl symptoms. Get support from your family and friends by informing them your intention to quit, and avoid situations and people who may tempt you to smoke.