A human brain can survive for only an average of five minutes without oxygen before it becomes permanently damaged. When used properly, CPR can dramatically increase a person’s chances of making a full and complete recovery, even after a serious injury or problem. Simply allowing a person to lie still while waiting for help can increase their risk significantly. Also, CPR is a way to take a proactive approach to a frightening and stressful situation. It’s one of the easiest things you can learn that can make a true difference in another person’s life. Taking a periodic refresher course on CPR and other first aid strategies is highly recommended, too, since you hopefully won’t need to use it all that often in your regular life.