High Altitude Sickness(AMS)

Altitude sickness, also known as acute mountain sickness (AMS), altitude illness, or soroche, is a pathological condition that is caused by acute exposure to low air pressure (usually outdoors at high altitudes). It commonly occurs above 2,400 metres (approximately 8,000 feet). Acute mountain sickness can progress to high altitude pulmonary edema or high altitude cerebral edema.
AMS is very common at high altitude. At over 3,000 meters (10,000 feet) 75% of people will have mild symptoms. The occurrence of AMS is dependent upon the elevation, the rate of ascent, and individual susceptibility. Many people will experience mild AMS during the acclimatization process. The symptoms usually start 12 to 24 hours after arrival at altitude and begin to decrease in severity around the third day.
The symptoms of Mild AMS include:

• Headache
• Nausea & Dizziness
• Loss of appetite
• Fatigue
• Shortness of breath
• Disturbed sleep
• General feeling of malaise

Symptoms tend to be worse at night and when respiratory drive is decreased. Mild AMS does not interfere with normal activity and symptoms generally subside within two to four days as the body acclimatizes. As long as symptoms are mild, and only a nuisance, ascent can continue at a moderate rate.

 

The altitudes of different places in Tibet:

Place Altitude Place Altitude Lhasa 3658 m 12001 ft Nyingchi 3000 m 9843 ft Nagqu 4507 m 14787 ft Tsedang 3500 m 11483 ft Qamdo 3205 m 10515 ft Xigatse 3836 m 12585 ft Damshung 4200 m 13780 ft Gyangtse 4040 m 13255 ft Pome 2750 m 9022 ft Tingri 4300 m 14108 ft Amdo 4800 m 15748 ft Zayui 2325 m 7628 ft

Tips to avoid AMS

1. Do not overexert yourself or more higher for the first 24 hours.

2. If you begin to show symptoms of moderate altitude sickness, don't go higher until symptoms decrease.

3. Stay properly hydrated. Acclimatization is often accompanied by fluid loss, so you need to drink lots of fluids to remain properly hydrated.

4. Take it easy and don't overexert yourself when you first get up to altitude. But, light activity during the day is better than sleeping because respiration decreases during sleep, exacerbating the symptoms.

5. Avoid tobacco, alcohol and other depressant drugs including, barbiturates, tranquillisers, sleeping pills and opiates such as dihydrocodeine. These further decrease the respiratory drive during sleep resulting in a worsening of symptoms.

6. Remember: Acclimatisation is inhibited by overexertion, dehydration, and alcohol.

7. Prepare some AMS pills according to your doctor's suggestion.

8. Do exercises to keep you fit before coming to Tibet.

Who can't go

Everyone should have more or less altitude symptoms. However, those who have the following symptoms may not going to Tibet

1. something relating to Tuberculosis, pneumonia, serious tracheitis, bronchitis
2. Serious heart attack, high blood pressure
3. have already got a serious cold