Why should a person breathe in a paper bag when he or she is hyperventilating abnormally?

Breathing into a paper bag can help a person who is hyperventilating by increasing the concentration of carbon dioxide in the blood, which can counteract the effects of rapid, shallow breathing. This practice encourages slower, more controlled breaths and can help alleviate feelings of dizziness and anxiety associated with hyperventilation. However, it should be noted that this method is not suitable for everyone and should only be used in non-serious cases, as it may not address underlying issues. Always consult a healthcare professional if hyperventilation is frequent or severe.