Medically reviewed by Chris Vincent, MD Everyone experiences boogers (dried phlegm) daily. They may seem gross, but boogers are an essential part of your body's immune system. But what are boogers ...

And as you continue to breathe, air hardens the mucus into a solid booger, a gooey prison cell ... The next time you feel the urge to mine for green gold, just grab a tissue.

In the final phase of boogerfication, the mucus, dirt, and other junk dry up and clump together, forming the nasal classic-- the booger.