Nepal has as low as 59 meters (194 ft) elevation in the tropical Terai to the northern rim of the Gangetic Plain, beyond the perpetual snow line to some 90 peaks over 7,000 meters (22,966 ft) including Earth’s highest 8,848 meters (29,029 ft) Mount Everest. The elevations ranging from less than 100 meters (300 ft) to over 8,000 meters (26,000 ft) and precipitation from 160 millimeters (6 in) to over 5,000 millimeters (16 ft) the country has eight climate zones from tropical to perpetual snow.
The higher altitude you get, the lower the amount of the oxygen makes difficulty in breathing and walking. One needs to acclimatize their body to higher altitude. Since most of the trekking routes in Nepal are at higher elevations so one can experience altitude sickness. It is highly recommended to acclimatize your body in order to avoid some fatal obstacles though trek itineraries are carefully prepared with enough acclimatization days to avoid AMS. Mild headaches, fever, loss of appetite or stomach disorder are symptoms of altitude sickness. Trek guides are well trained to administer altitude sickness. We highly advise person with known heart, blood or respiratory diseases to consult their medical professional before joining any high-altitude treks.