As you've already learned, two of the most important rules in scuba diving are "never hold your breath" and "equalize your ears early and often." Following these rules helps prevent injuries called barotraumas, which are injuries caused by pressure changes inside any of the body's air spaces.

Your lungs and ears aren't the only air spaces that are susceptible to barotrauma. Your sinuses, face, and in rare cases teeth can be damaged by changes in pressure. In this lesson, you'll learn about pressure-related injuries that can occur, how to prevent them, and proper first aid procedures to follow in the event an injury does occur.