Why do people who suffer from an anxiety attack breath inside a paper bag?

People, why do you answer when you don’t know what you’re talking about? Breathing into a paper bag is for hyperventilation, not anxiety attacks. (Although they may occur together.) The point of breathing into a paper bag is that when you breathe too fast, you blow off too much CO2. CO2 is the major chemical that tells the brain stem (pons and medulla) to intiate a breath. Therefore, hyperventilation can actually STOP breathing. In addition, too little CO2 in the blood causes an increased pH measurement known as respiratory alkalosis, which is not a good situation.

Lead – US Zeitgeist 2010