Your nose, voice box, throat, windpipe and lungs, or Respiratory System is uniquely designed to help you breathe in oxygen and expel carbon dioxide so that you can live.   Even if you live in China or L.A. and the air is terribly polluted, your Respiratory System is designed to filter out the bad elements from your body, while the good oxygen brings nutrients to your cells, and you can sustain life.  If you smoke, the ingredients contained in tobacco begin to contaminate your lungs.  The small airways become constricted and your body builds up mucus that it can’t get rid of, and breathing becomes very difficult. The lungs of teens are still growing but if they smoke, the lungs will be smaller in size and prone to disease.  Your cells are robbed of oxygen if you smoke, and that means that you will have many health issues.  Of course, smoking is a known cause of Lung Cancer, which has a very high mortality rate.  There is no doubt that the chances of your getting extremely ill and dying are greatly enhanced by your fatal smoking habit.