Why do American movies and TV shows feature characters breathing into a paper bag when stressed? They struggle with hyperventilation. During panic or hysteria people frequently breathe rapidly (hyperventilation). In this case, the blood contains too much oxygen and not enough carbon dioxide, resulting in impaired brain function, dizziness occurs, the person may faint. The easiest way out is to breathe into the bag, i.e. to inhale your own breath, while the content of gases in the blood remains normal. Excessive oxygen and little carbon dioxide excites the brain, which again leads to increased breathing and exacerbates the vicious circle. I have no idea why nobody does this in our country – apparently, no paper bags are available.