Altitude Illnesses include:
Altitude illness: Altitude sickness, also known as acute mountain sickness (AMS), altitude illness, hypobaropathy, or soroche, is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2,400 metres (8,000 feet).
Extreme Hypoxia: Hypoxia is a pathological condition in which the body as a whole (generalized hypoxia) or a region of the body (tissue hypoxia) is deprived of adequate oxygen supply.
Hypoxemia: An abnormal deficiency in the concentration of oxygen in the blood.
Hypocapnia: Hypocapnia or hypocapnea also known as hypocarbia, sometimes incorrectly called acapnia, is a state of reduced carbon dioxide in the blood. Hypocapnia usually results from deep or rapid breathing, known as hyperventilation.
When climbing it is important to recognize the onset of symptoms that indicate something is wrong. Typical symptoms include: fatigue, dizziness, nausea, atypical sleep patterns, headaches
Other symptoms appear in more severe instances.