At least three trekkers die per year from AMS, generally known as High Altitude Sickness, and it is the most important medical concern while Trekking in the high Himalayas of Nepal. High altitude sickness refers to the effect of altitude on those who ascend rapidly to elevations above 2500 meters (8200ft). The occurrence of AMS, commonly known as Acute Mountain Sickness, depends on elevation, the rate of ascent, and individual susceptibility. Many people will experience mild symptoms of Acute Mountain Sickness during the acclimatization process, and this is actually more common in fit young people because they are more likely to try a fast climb by racing up the mountain like some indestructible super hero!
Some people are more vulnerable to altitude than others. If you know you get altitude sickness easily, it is crucial to adjust your acclimatization schedule accordingly while doing a trek like Everest Base Camp, or use preventive medicine (Diamox/Acetazolamide). Awareness of altitude sickness has led some trekkers to feel unnecessarily anxious during their treks. As a general rule, it is always recommended to walk gently for a safer and more enjoyable trek and avoid high altitude sickness by planning a sensible itinerary that allows for steady acclimatization to altitude as you climb up, but you could run back down as fast as you like!
Our body has the ability to adjust to higher altitudes if given enough time. This process of adaptation is called acclimatization. Altitude illness occurs as a result of failure to adapt to a higher altitude. Fluid begins to leak from blood vessels, most often in the brain or in the lungs. If fluids collect in the lungs, you become breathless more easily while walking. A cough begins first as dry and irritative, but progresses to the production of pink, frothy sputum in its most severe form. The person ultimately drowns in this fluid if he/she doesn't go down.
This symptom is referred to as high altitude pulmonary oedema (HAPE). When fluid leaks in the brain, you initially develop a headache, loss of appetite, nausea, and vomiting. This symptom is referred to as acute mountain sickness (AMS). If you become more tired and you like to lie down and do nothing, as you lose coordination, and eventually you fall into a coma, and death is inevitable if you don't descend immediately. This syndrome is called HACE. HAPE and HACE can occur alone or in combination.
The following are the main symptoms of AMS:
- Nausea, vomiting, Loss of appetite.
- Disturbed sleep/Insomnia, persistent headache.
- Dizziness, lightheadedness, confusion, disorientation, drunken gait.
- Weakness, fatigue, lassitude, heavy legs, and slight swelling of hands and face.
- Shortness of breath and breathing irregularity, reduced urine output.
- General feeling of malaise
These symptoms must be taken very seriously. In case of the appearance of any of the above-mentioned symptoms, any further ascent should be avoided; otherwise, more serious, even life-threatening troubles may happen. The only cure for Altitude Sickness is to descend to lower elevations immediately. Acclimatization by ascending to no more than 300 to 500 meters per day above your "acclimatization line", and the proper amount of rest and dehydration are the best methods for prevention of AMS. So, a gentle ascent is always pleasing to try to avoid acute mountain sickness. The trekking itineraries on this site are designed to ensure maximum enjoyment of the trek and to minimize possible hazardous situations.
Some basic guidelines for the prevention of AMS:
- Don´t fly or drive to high altitude.
- Start from below 2500 meters and walk up.
- Climb high and sleep low!
- Increase your altitude by 300-500 meters per day only.
- Stay properly hydrated and drink enough water.
- Urine output should be copious and clear to pale yellow.
- Avoid tobacco, alcohol, and other depressant drugs.
- Eat a high-calorie diet while at altitude.
- If someone is sick in a group, they shouldn’t be left behind.
- He/she needs help and care.
- If symptoms are appearing, GO DOWN, DOWN, DOWN!
In conclusion, there is no need to worry about high altitude sickness for a perfect trek; light activity during the day is better than sleeping because respiration decreases during sleep, exacerbating the symptoms. You may like to know about some important tips for making a Nepal trek successful with a happy ending. Here is the link