Many people are concerned about altitude sickness. This problem, often known as acute mountain sickness (AMS), is a particularly important medical consideration while trekking in Nepal and Tibet.
AMS rarely occurs lower than 2800 meters (9520ft) and only minor symptoms occur below 4000 meters (13,800ft).
AMS occurs when the body does not adapt well to the lack of oxygen present at higher altitudes. At 5490 meters (@18,000ft), there is just half the oxygen available as there is at sea level, while there is only a third available at the summit of Mount Everest.
What happens to the body during altitude illness?
Fluids accumulate in between the cells in the brain, the lungs or both, creating mild to severe symptoms. Mild symptoms include headache, loss of appetite, nausea, fatigue, insomnia and dizziness. These symptoms are usually resolved by spending one or two extra nights at the same altitude. If symptoms worsen, descent to lower altitudes is warranted. If you are resting at the same altitude and your symptoms worsen, then it is also necessary to descend.The body tries to adapt to having less available oxygen by increasing the rate and depth of breathing, as well as the heart rate.
More serious symptoms of AMS include increased tiredness, severe headaches, vomiting, loss of coordination, shortness of breath and coughing fits. These extremely dangerous symptoms are called high altitude cerebral edema (or HACE). They can lead to unconsciousness and death within 12 hours. Increasing shortness of breath, cough and tiredness may also be signs of high altitude pulmonary edema or HAPE. This condition can rapidly prove to be fatal if ignored. Respiratory depression (the slowing down of breathing) can be caused by various substances, and may be a problem at altitude.
The following substances can do this, and should never be used by someone who has symptoms of altitude illness:
- Sleeping pills (acetazolamide is the sleeping tablet of choice at altitude)
- Narcotic pain medications in more than modest doses
To prevent AMS and respiratory depression, drink at least three liters of liquid a day and avoid getting cold. Altitude sickness can to a certain extent be prevented by acetazolamide (Diamox SR), 750mg per day. Some experts suggest a two-day trial of acetazolamide before the trip. Please seek the advice of your personal physician. Please note that taking Diamox SR does not mean that you can ignore advice about proper acclimatization.
Serious symptoms of altitude sickness include:
- A severe, enduring headache, which is not cured by ordinary painkillersm
- Nausea and repeated vomiting
- Irritating dizziness or actual difficulty with balance and direction
- Visual disturbances with flickering vision and problems judging distance
- Pressure in the chest, rapid breathing and pulse rate, crackles in breathing and shortness of breath
- Swelling beneath the skin (edema), typically around the eyes
- Swollen ankles and hands
In the presence of these symptoms, medical attention must be sought immediately in conjunction with descent to the lowest possible height. We have guides trained at the High Altitude Medical Training Center. Our staff is very experienced in dealing with the effects of higher altitudes. As they are natives of Nepal, they easily acclimatize and therefore can care for their clients. They are equipped with necessary medical supplies and will assist with basic first aid treatment. We design our tours to ensure clients are ready for high altitude, and arrange alternative itineraries for those at risk.