Acute Mountain Sickness – Cause & Effect

AMS or acute mountain sickness is actually more common in fit young men. This is because they are more likely to attempt a rapid ascent by racing up the mountain like some indestructible super hero. Also as a general rule, it is far safer (and more enjoyable) to avoid altitude sickness by planning a sensible itinerary. Furthermore itinerary that allows for gradual acclimatization to altitude as you ascend.

The pleasures of trekking in the world’s highest mountain ranges cannot be overstated. Neither can the dangers. Altitude sickness can occur in some people as low as 8,000 feet, but serious symptoms do not usually occur until over 12,000 feet. Even then it is not the height that is important, rather the speed in which you ascended to that altitude.

High Altitude Categorization

2,500 to 4,000 metres
8,000 to 13,000 feet
Very High
4,000 to 5,500 metres
13,000 to 18,000 feet
Extremely High
over 5,500 metres
over 18,000 feet


It is difficult to determine who would face trouble while going up the altitude belt. Some people get it and some people don’t because some people are more susceptible than others. Most people can ascend to 2,500 meters (8,000 feet) with little or no effect. If you have been at that altitude before with no problem, you can probably return to that altitude without problems as long as you are properly acclimatized. If you haven’t been to high altitude before, you should exercise caution when doing so.

Why does it happen?

The percentage of oxygen in the atmosphere at sea level is about 21% and the barometric pressure is around 760 mmHg. As altitude increases, the percentage remains the same but the number of oxygen molecules per breath is reduced.

In addition, high altitude and lower air pressure causes fluid to leak from the capillaries in both the lungs and the brain which can lead to fluid build-up. Continuing on to higher altitude without proper acclimatization can lead to the potentially serious, even life-threatening altitude sickness.

Effects Of AMS

The symptoms of Mild AMS include:

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


Keep in mind the below mentioned points and you would have better chances of retaliating against AMS. Also make sure that in case you feel a bit strange, come down.

Acute mountain sickness
Acute mountain sickness

In our last trip we ran into a trouble when our friend had severe AMS. Luckily we had a doctor at nearby camp in Chandratal. However not always are people lucky. Keep in mind the above mentioned points and you will be just fine.