When you hyperventilate (breathe too fast), respiratory alkalosis (decreased concentration of hydrogen ions in the blood) can occur, which can cause you to faint. A common but potentially dangerous method to reverse respiratory alkalosis is to hold a paper bag over your mouth and take normal breaths, thereby rebreathing the exhaled air. How might this method reverse respiratory alkalosis?

Question

Quizplus · Accepted Answer

Holding a paper bag over the mouth and breathing normally will cause the person to inhale carbon dioxide that was exhaled into the bag. This will increase the concentration of carbon dioxide in the blood and cause it to react with water to form carbonic acid. Carbonic acid is a weak acid, and an increase in its concentration will cause blood pH to decrease, therefore reversing the respiratory alkalosis.

When You Hyperventilate (Breathe Too Fast), Respiratory Alkalosis (Decreased Concentration