Oxygen therapy

[Zipporah Schumaker]

Oxygen is a gas that makes up about 21% of the air we breathe. The lungs take oxygen from the air and transfer it to the bloodstream (see Exchanging Oxygen and Carbon Dioxide). Oxygen is needed to burn fuel to release energy, such as in a car engine. Similarly, all living tissue needs oxygen to provide energy for the body. Without enough oxygen, cells function poorly and eventually die.

Many diseases, particularly lung diseases, decrease the amount of oxygen in the bloodstream. In such cases, people may benefit from being given extra oxygen. Doctors used to give extra oxygen to many sick people. However, evidence has shown that oxygen is not helpful unless a person