Smoking is a chronic of organism intoxication. Nicotine, which is contained in tobacco, is regarded to be one of narcotic substances. It does not cause the state of euphoria, which is typical to alcohol and other drugs, but the ability to provide physical and mental habit it has the same as other drugs. The development of tobacco dependence is associated with the age, when people starts smoking, experience, frequency of smoking, with the peculiarities of the organism and the nature of the smoker. The earlier you started smoking, and the longer the length of smoking, the faster and stronger than the tobacco dependence.

Tobacco poisons Control penetrates into a smoker’ body, their devastating effects is reflected in tissues, but many smokers for many years, do not feel much change in mood. Intrigue of smoking is that serious consequences develop gradually and imperceptibly to himself a smoker.
  
Sooner or later every smoker feels the consequences of smoking. They take measures after the appearance of cough, shortness of breath, weakness in the legs, and pain in the heart.

When smoking tobacco by means of the lungs alveoli nicotine penetrates into the bloodstream and within 10 seconds reaches the brain. Rapid spreading of nicotine in the lungs is primarily connected with the sharp increase of its concentration in the blood to, 20-50 ng per ml and then it gradually decreases. The period of nicotine influence in the body is 1-2 hours. Nicotine concentration reduction in the blood  which is lower than an ordinary level stimulates the necessity in its further application in order to maintain their regular level.

After 4-6 hours from the start of tobacco use, the concentration of nicotine in the blood goes to excessive level and is maintained as long as the person smokes. Cigarette length reducing or a decrease of nicotine concentration in it leads to an unconscious increase of smoking intensity, shown by increased frequency and process of puffs. After smoking one cigarette approximately 1 mg of nicotine penetrates into the body (one cigarette nicotine concentration is about 1.8 mg). You should remember that smoking is a constantly repeating habit.

   It must be borne in mind that smoking - is a constantly renewable behavior. Quitting tobacco can only stop the use of nicotine, but it does not exclude nicotine addiction.