The air a person normally breathes contains approximately 21 percent oxygen. The concentration of oxygen delivered to a victim through rescue breathing is 16 percent. A condition known as hypoxia (insufficient oxygen to the body) can occur if a person goes without adequate oxygen for an extended period.
Signs and symptoms of hypoxia include:
- Increased breathing and heart rate
- Changes in level of consciousness
- Cyanosis (bluish color on lips and nailbeds)
- Chest pain