An altitude over 3,000 meters (9,843 feet) is usually defined as high altitude. Since most places in Tibet are higher than this level, Acute Mountain Sickness (AMS), also called Altitude Sickness is the biggest health risk to tourists in Tibet

The following precautions may help to prevent or lessen the effects of AMS:
1.Since fluid loss usually accompanies the acclimatization process, drink plenty of fluids (3 - 4 litres daily at least) and eat carbohydrate food to keep the body properly hydrated;
2.Do not over exert and only partake in light activity immediate after your arrival;
3.Don't smoke, drink alcohol or take other depressants such as tranquilizers and sleeping pills. These will depress the respiratory drive and limit oxygen intake. Always keep in mind the following rules which will ensure a smooth and enjoyable trip to Tibet:
4.Any sickness at high altitude is AMS until proven otherwise; · Never go higher with symptoms of AMS;
5.It is significant that you report any symptoms of AMS immediately to other group members in the trip.