High Altitude

The High Altitude is commonly referred as:-
- High Altitude: 1500 - 3500 m (5000 - 11500 ft)
- Very High Altitude: 3500 - 5500 m (11500 - 18000 ft)
- Extreme Altitude: above 5500 m

However we rarely worry about elevations below about 2500 m (8000 ft) since altitude illness rarely occurs lower than this.