http://www.webcitation.org/5zEnyu7K2[/URL]]Acclimatization is the process of the body adjusting to the decreased availability of oxygen at high altitudes. It is a slow process, taking place over a period of days to weeks.
High altitude is defined as:
- High Altitude: 1500 - 3500 m (5000 - 11500 ft)
- Very High Altitude: 3500 - 5500 m (11500 - 18000 ft)
- Extreme Altitude: above 5500 m
Practically speaking, however, we generally don't worry much about elevations below about 2500 m (8000 ft) since altitude illness rarely occurs lower than this.
Certain normal physiologic changes occur in every person who goes to altitude:
- Hyperventilation (breathing faster, deeper, or both)
- Shortness of breath during exertion
- Changed breathing pattern at night
- Awakening frequently at night
- Increased urination