We all have habits, good or bad. Some of them are a bit strange: reading magazines back to front, for instance. Others can be annoying: like biting your nails or being always late. You are lucky if you have only good and healthy habits: jogging every morning or brushing your teeth after meals. Unfortunately many people have bad habits which mainly cause serious health problems. The most common habits are smoking, drinking alcohol and using drugs. They usually come out as a result of some stress, anger or boredom. Some teenagers start smoking because they believe that it’s cool. Bad habits are dangerous and expensive. What is more, for many people they are addictive. It means that it’ll be very hard to quit them once you have started.