Sudden cardiopulmonary arrest is the leading cause of death for all adults.

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You're playing your usual weekend pickup basketball game with friends. Without warning, one of your teammates suddenly crumples to the ground. You scream out his name, but there's no response. His face turns pale and blue, and you can't see his chest rise and fall. You listen for a heartbeat, but you can't find a pulse at all. You quickly grab your cell phone and dial 911.

Sudden cardiac arrest -- or sudden cardiopulmonary arrest as it's also known -- is the leading cause of death in the United States, killing more than 325,000 men and women every year [source: Mayo Clinic]. Fortunately, modern medicine has come up with a number of tools to help revive those who experience sudden cardiac arrest. Many of these emergency procedures require medical training and/or complex equipment; but one -- cardiopulmonary resuscitation (CPR) -- needs no additional devices and can be performed by a layperson with only a little bit of training.

In this article, we'll explore how this first aid technique can help save lives.

PLEASE NOTE: This article is not intended to be used as a method for teaching CPR. For proper CPR training, consult your local hospital or American Red Cross chapter for available classes.