An addiction causes a sufferer to experience physical or mental symptoms as a result of a dependence on a substance, behaviour or activity. They have no control over their actions and are controlled by the source of their addiction. This continues to the point where the sufferer is unable to function on a daily basis unless they have their fix Their lives are dominated by their addiction .They persist in their habit, knowing that it is dangerous to their health, but feel powerless to resist. When you engage in activities that make you feel happy, shopping spree, winning a bet or having sex with someone new ,your brain releases feel-good chemicals that encourage you to repeat that behaviour because it provides such an enjoyable high.