You breathe without thinking because your body does it for you
automatically. But things can change your breathing pattern and make you feel short of breath, anxious, or ready to faint. When this happens, it’s called
hyperventilation, or overbreathing.
That’s when you inhale much deeper and take much faster breaths than normal. This deep, quick breathing can change what’s in your blood. Normally, you breathe in oxygen and breathe out carbon dioxide. But when you
hyperventilate, the carbon dioxide levels in your bloodstream drop too low. You’ll notice it right away because you’ll start to feel sick.