Hypoxia
Hypoxia means low oxygen, and is a state of oxygen
deficiency in the body that is sufficient to cause an impairment of function.
For example, altitude sickness can be a hazard for aviators
and mountaineers, where hypoxia develops gradually.
Symptoms of hypoxia depend on its severity and acceleration
of onset. They include headaches, fatigue, shortness of breath, a feeling of
euphoria and nausea.
Hypoxia can cause damage to the brain.