Cardiopulmonary resuscitation (CPR) is given when someone's breathing or pulse stops. If both have stopped, then sudden death has occurred. Some of the causes of sudden death include poisoning, drowning, choking, suffocation, electrocution, or smoke inhalation. But, the most common cause of sudden death is from heart attack. Despite the fact that CPR is proven to save lives — patient recovery rates are better when bystanders initiate resuscitation and there’s a greater likelihood of survival with less damage to heart muscles and the brain — studies suggest that less than one-third of people experiencing cardiac arrest outside of a medical center receive the help they need. If you or someone you know has any of the above warning signs, act immediately. Call your local emergency number. If needed, give CPR if you are trained, or ask someone who is.