what happens if you smoke 5 cigarettes a day Many people think smoking only on the weekends or at parties is harmless, but doctors warn there is no safe amount of tobacco. Find out how even occasional smoking damages your heart Pack Years of Smoking and

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Smoking can make symptoms from cancer treatment worse, and can even make treatments less effective Image content: This image is available to view online

Teenagers crave the reward drug, dopamine , which is generated by risk, challenge, recognition, exercise and collaboration

Data from a 2002 survey show that more than 9 out of 10 smokers agreed or strongly agreed with the statement, If you had to do it over again, you would not have started smoking. Further, 7 out of every 10 smokers reported that they wanted to quit smoking, and more than half of all smokers stopped smoking for at least one day with the intent of quitting permanently