Hyperventilation is breathing much faster and deeper than your body actually needs. When someone hyperventilates, they're taking rapid, gasping breaths that change the balance of oxygen and carbon dioxide in their blood.

This usually happens when someone is panicking, extremely anxious, or very frightened. You might see someone hyperventilating after a scary experience, breathing so fast they can barely speak. The extra-fast breathing can make them feel dizzy or lightheaded, and their fingers might tingle. Ironically, even though they're taking in lots of air, hyperventilating can make people feel like they can't breathe, which can make them panic even more.

Hyperventilation can also happen during intense physical exercise if someone breathes too rapidly for what their body needs. People sometimes slow it down by calming themselves and taking slower, steadier breaths.