Altitude illness (Acute Mountain Sickness - AMS)

It is a condition caused by rapid ascents to high altitudes and the altitude sickness increases for most people at around 3,000m above sea level and some can experience altitude illness symptoms even lower elevation and there is no correlation between age, fitness level, health conditions, gender and experiences of going to high altitude as climbing more than 500m a day then there is probability of altitude illness.

High Altitude Cerebral Edema (HACE)

it is a severe altitude sickness condition and occurs when pressure build-up in the brain results in fluid breaching the capillary walls in the cranium and It is a rare condition on general treks, but much more common among mountaineers in high altitude mountain ranges such as the Himalayas.

High Altitude Pulmonary Edema (HAPE)

It is another fatal altitude illness condition and occurs when fluid breaches the pulmonary capillaries and enters the lungs. Fluid in the lungs inhibits the effective exchange of oxygen to the blood.

Acclimatization on Trek

Acclimatization is a process to acclimatize your body with the high altitude, weather conditions, and get used lower levels of oxygen at altitude and it can be achieved only by spending extra time at various levels of altitude before progressing higher so, there is should be adequate extra days in trekking itinerary while you are planning high Himalayan trekking in Nepal.

Some common rules to avoid Mountain sickness

It is very important to know that severe altitude sickness like HACE and HAPE are rare on common treks in Nepal, only a some trekking in Nepal that go to extreme altitude (above 5,500m) in high country may have these extreme sickness, so, you should be worry already before starting trekking in Nepal that goes less than 5500 above sea level, more over we should follow some of the common rules to avoid sickness which are:

  • Get over high passes / summit climbs quickly and then descend.
  • If symptoms continue to worsen after resting at a certain altitude, continue to descend immediately, do not wait.
  • Make sure to have in adequate acclimatization days on your trekking itineraries.
  • Drink at least 3 litres of water a day.
  • Go slowly while trekking in High Mountain.
  • Please avoid alcohol and smoking while trekking.
  • Please arrange the trek with experienced and responsible trekking operator who understands the risks of altitude and have trained and experienced guide.
  • Consider taking a preventative medication like Diamox as an extra precaution.


it is clinically known as Acetazolamide, is a prescription drug that effectively helps mitigate altitude illness on trek and It is a preventative medication not a cure as this helps with promoting faster acclimatization and thus prevents the potential onset of altitude illness, but does not cure it. It is always better to visit doctor before start trekking and use according to the doctor’s prescription however you can buy over the counter at a pharmacy however we recommend you consult your doctor before using it and the drug should not be taken by pregnant women or people with kidney and liver issues.

Travel and Trekking Insurance

As you are already aware that the high altitude trekking comes with obvious risks so, we strongly recommend that you get adequate travel and trekking insurance while you taking trekking in Nepal and in the case of having sickness in Mountain trekking in Nepal, there is not any other option rather than taking evacuation back to city and visit doctors and this types of rescue by the helicopter in Nepal is expensive so, we advise you to have insurance that cover these expenses.