Altitude and Acclimatization in Himalayas

Our itineraries are suspiciously planned to make you sure there is a steady climb in height over a number of days to permit for the necessary time for your body to acclimatize to high altitude. Most people can hike to 2,500m without a problem however it is impossible to decide who might be more at risk to altitude sickness at higher altitudes. No single factor such as age, sex or fitness will affect your likelihood of being affected.

The Cause of Altitude Sickness

As the elevation increases the partial pressure of oxygen is reduced, such as 3,600 there is about 40% less oxygen than at sea level. The body must normalize to having less oxygen.

Acclimatization

Acclimatization is the process of the times in which the human body can adapt to the decrease of oxygen at higher altitude. Hiking too high in a short time can results altitude sickness. Several mechanisms of body adjust to less oxygen, the main ones being an increasing rate and depth of breathing followed by the slower process of producing more red blood cells.

Mild Acute Mountain Sickness

At mild acute mountain sickness (AMS), the spectrum of altitude sickness starts. During the acclimatization process many people will experience mild AMS. The symptoms of mild AMS include:

Nausea & dizziness ·
Headache ·
Loss of appetite ·
Fatigue ·
Shortness of breath ·
Disturbed sleep

Symptoms are likely to be worse at night when your breathing rate decreases. As long as symptoms are mild and only an irritation to your incline can continue at a reasonable rate. It is very important that you talk any symptoms of illness to the Leader of your trip.

Moderate AMS

The best test for reasonable AMS is get the person to walk in a straight line heel to toe, if they are unable to do this then an immediate descent is required. Often only a small decrease in altitude of 300m will relieve the symptoms.

The signs and symptoms of Moderate AMS include:

Severe headache that is not relieved by medication ·
Nausea and vomiting,
increasing weakness and fatigue ·
Shortness of breath ·
Decreased coordination (ataxia)

Severe AMS

Severe AMS has two serious conditions one being high altitude intellectual edema and the other high altitude pulmonary edema. These should not occur if a sensible acclimatization schedule has been adhered to and usually happens due to people going too high too fast. In both cases the lack of oxygen results in leakage of fluid through the capillary walls into either the lungs or the brain.

Symptoms of High Altitude Pulmonary Edema (HAPE):

Shortness of breath at rest ·

Tightness in the chest, and a persistent
cough bringing up white,
watery, or frothy fluid ·
Fatigue and weakness ·
Confusion, and irrational behavior

Symptoms of High Altitude Cerebral Edema (HACE):

Headache ·
Disorientation ·
Loss of coordination ·
Confusion and irrational behavior ·
Decreasing levels of consciousness ·
Loss of memory ·
Hallucinations ·
Coma

Instant descent is necessary for someone with HACE and/or HAPE. There is also medication that may be used for treatment.

Guidelines for the prevention of AMS

The guidelines state that when you get above 3,000 meters, you should increase your elevation by approx. 300 meters per day, and for every 900 meters of elevation increased take a rest day.

If you have symptoms of moderate AMS do not go higher until symptoms decrease. ·
If symptoms increase, descend immediately! ·
Remember that people acclimatize at different rates. ·
Make sure you are properly hydrated by drinking at least four liters per day.
Urine should be copious and clear to pale yellow ·
Do not over exercise yourself at altitude