The letters in CPR stand for CardioPulmonary Resuscitation, a combination of rescue breathing (mouth-to-mouth resuscitation) and chest compressions. If a person is not breathing or not circulating blood adequately, CPR can restore circulation of oxygen-rich blood to the brain. Without oxygen, permanent brain damage or death can occur in less than 8 minutes. Heart attack and heart disease, including sudden cardiac arrest, is the leading cause of death in adults. Most cardiac arrests occur in persons with underlying heart disease.

CPR doubles a person's chance of survival from sudden cardiac arrest. 75% of all cardiac arrests happen in people's homes. The typical victim of cardiac arrest is a man in his early 60's and a woman in her late 60's.