Hyperoxia

Hyperoxia occurs when tissues and organs are exposed to an excess supply of oxygen (O2) or higher than normal partial pressure of oxygen.
In medicine, it refers to excess oxygen in the lungs or other body tissues, which can be caused by breathing air or oxygen at pressures greater than normal atmospheric pressure. This kind of hyperoxia can lead to oxygen toxicity, caused from the harmful effects of breathing molecular oxygen at elevated partial pressures. Hyperoxia differs from hypoxia in that hyperoxia refers to a state in which oxygen supply is too much, whereas hypoxia refers to the state in which oxygen supply is insufficient.