What Nicotine Is

• Nicotine is an alkaloid found in tobacco. It occurs in the tobacco roots and accumulates in the leaves. It constitutes between 0.6 and 3 percent of the tobacco's weight. In the past, nicotine was used as an insecticide because of its antiherbivore chemical functions. Even today, some insecticides contain nicotine or nicotine analogs.
  
  

The Addiction

• Nicotine is physically and psychologically addictive. Small droplets of nicotine enter the body with the inhaled smoke. When it reaches the lungs, nicotine follows the bloodstream, entering the brain in 10 seconds. In the next 5 to 10 seconds it reaches the rest of the body. After 30 minutes, the nicotine leaves the bloodstream, causing the smoker to desire another dose of nicotine. The American Heart Association considers nicotine addiction one of the hardest to break.
  
  

Nicotine Affects the Entire Body

• Nicotine raises heart rate and blood pressure. The blood sugar level is elevated and the production of insulin is increased because of nicotine. Nausea, sweating and diarrhea may also occur. Inexperienced users might experience tremors, as nicotine stimulates the nervous system. In high doses, nicotine might even cause convulsions.
  
  

Signs of Nicotine Withdrawal

• When a person tries to quit smoking, the first reaction caused by nicotine is the urge to smoke. The lack of nicotine in the body will make people feel depressed and irritated, frustrated or angry. It also causes insomnia and anxiety and decreases the heart rate. Some people find it difficult to concentrate, and they gain weight after quitting smoking.
  
  

Nicotine Replacement Therapy

• There are products and programs available that help people break their nicotine addiction. One such help is nicotine replacement therapy (NRT). It is a safe and effective way to help people stop smoking. You can use products, such as gum, patcesh, inhalers and nasal spray, that contain nicotine or alternatives. The therapy combines the use of these products with behavior change and support (such as self-help booklets and telephone counseling).