This text does not mean to scare you away, but rather to warn you of dangers that you can face with little problems if you take some simple precautions.

Generally altitude over 3,000 meters (9,843 feet) is defined as high altitude. Since most places in Tibet are higher than that level, Acute Mountain Sickness (AMS), also called Altitude Sickness is the biggest health threat to tourists in Tibet. AMS is common at high altitudes due to the decreasing availability of oxygen. It is usual that most people will experience symptoms at different levels at that high elevation. The occurrence of AMS is dependent on the altitude, the ascent rate and individual physical condition. Symptoms of AMS include headache, nausea, dizziness, fatigue, shortness of breath, loss of appetite and disturbed sleep. Many people will experience one or more AMS symptoms upon their arrival in Tibet. The symptoms will usually decrease in severity gradually during the acclimatization. Mild AMS is usual and will not interfere with mild activity.

However AMS can be very serious. The most serious symptoms are High Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE), which can be fatal. Symptoms of HAPE include weakness, shortness of breath, even at rest, impending suffocation at night, and a persistent productive cough with white, watery, or frothy fluid. Symptoms of HPCE may include headache, ataxia, weakness, hallucinations, psychotic behavior, coma and loss of memory. Both approach and strike at night and can be fatal! Immediate descent is the surest treatment.

Before visit to Tibet, get as fit and healthy as possible, both physically and psychologically. Visitors having record of heart, lungs and other organ problems or anemia should consult their doctor before making the decision to visit Tibet.
AMS can be lessened or avoided. Proper acclimatization can also ease and reduce AMS symptoms. A gradual ascent will allow your body to acclimatize to higher altitudes and the decreased oxygen supply. Go higher 300 - 400 hundred meters (984 - 1,312 feet) daily and have a rest after every 1,000 meter (3280 feet) ascent. Medication also helps to prevent AMS. Mild AMS symptoms can be cured with proper medication. Once medications do not respond to the symptoms, go to hospital or evacuate immediately to safe altitude!

The following precautions may help to keep AMS away from you:

Since fluid loss usually accompanies the acclimatization process, drink plenty of fluids (3 - 4 liters daily at least) and eat carbohydrate food to maintain properly hydrated;
Do not over exert and maintain light activity right after your arrival;

Stay way from smoking and alcohol and other depressants such as tranquilizers and sleeping pills, which will depress the respiratory drive and oxygen intake.
Always keep in mind the following rules which may ensure you a smooth and enjoyable trip to Tibet:
Any sickness at high altitude is AMS until proven otherwise; Never go higher with symptoms of AMS;

It is significant that you report any symptoms of AMS immediately to other group members in the trip.